<PAGE>
                                                                   EXHIBIT 10.19

[MEMORY COMPANY LOGO]

MEMORY PHARMACEUTICALS CORP.                             JOANNE LEONARD
100 PHILIPS PARKWAY                                      SENIOR VICE PRESIDENT
MONTVALE, NEW JERSEY 07645                               CHIEF FINANCIAL OFFICER
PHONE: (201) 802-7102
FAX: (201)  802-7190
www.memorypharma.com





February 18, 2002

James E. Barrett, Ph.D.
1231 River Road
Washington Crossing, PA 18977

Dear Jim:

      We are pleased to extend an offer to you to join our Company as Senior
Vice President of Research and Development. We look forward to you joining our
team, and are confident that you will contribute significantly to the value of
our organization. The terms of your anticipated employment by the Company are as
follows.

      1. Position. Your position will be Senior Vice President of Research and
Development, based out of the Company's offices currently located in Montvale,
New Jersey, and will report directly to the Company's President and Chief
Scientific Officer. As Senior Vice President of Research and Development, you
will be part of the Company's senior management team, and will work closely with
this team to establish strategic, value-building relationships with
pharmaceutical companies and contract research organizations. Your
responsibilities shall include, but not be limited to, managing all research and
development activities up to clinical Phase IIa studies and managing post
collaboration interface on pivotal clinical trials. In addition to performing
duties and responsibilities associated with the position of Senior Vice
President of Research and Development, from time to time the Company may assign
you other duties and responsibilities and/or may assign you to a different
location.

      As a full-time employee of the Company, you will be expected to devote
your full business time and energies to the business and affairs of the Company.
Your performance will be reviewed formally after six months of employment and
annually thereafter at the end of each calendar year.

      2. Starting Date/Nature of Relationship. It is expected that your
employment will start on April 16, 2002 (the "Start Date"). No provision of this
letter shall be construed to create an express or implied employment contract
for a specific period of time. Either you or the Company may terminate the
employment relationship at any time and for any reason, by giving at least
thirty (30) days' prior written notice to the other party.

      3. Compensation.

      (a) Your initial salary will be at the bi-weekly rate of $10,576.92
(annualized at $275,000).

      (b) You will receive incentive stock options to purchase 300,000 Shares of
Common Stock of Memory Pharmaceuticals Corp. at $0.25 per share, which will vest
in quarterly increments over a period of four (4) years as described in the
Stock Option Agreement, which you and the Company will enter into on or before
the Start Date. You will receive additional incentive stock
<PAGE>

MEMORY PHARMACEUTICALS CORP.
James E. Barrett, Ph.D.

options to purchase Shares of Common Stock of Memory Pharmaceuticals Corp.,
immediately after the closing of the Company's Series D Financing at the then
fair market value to be determined by the Company's Board of Directors (without
affecting the purchase price of the initial grant of options to acquire 300,000
shares of the Company's Common Stock), with such additional option vesting to
commence on the date of such grant in quarterly increments over a period of four
(4) years. The additional incentive stock options to purchase Shares are being
provided to allow your percentage ownership before the Series D Financing not to
be substantially diluted.

      (c) You will be eligible to receive annual bonus payments dependent on the
performance of the Company and your individual performance, subject to the
discretion of the Board of Directors. Your target bonus will be equal to
twenty-five percent (25%) of your base salary, assuming the achievement of such
Company and individual performance objectives. You will receive a one-time
annual guaranteed bonus of $25,000, payable within 30 days of your one-year
anniversary.

      (d) Upon termination for any reason, the Company will pay you within two
weeks of such termination, your current base salary earned through the
termination date, plus accrued vacation, if any, and other benefits or payments,
if any, to which you are entitled. In the event you are terminated by the
Company, without "Cause" (as hereinafter defined), then the Company will
continue to pay you your bi-weekly rate in effect at the time of termination and
provide and pay the Company's portion of your medical insurance for a period of
six (6) months. Further, for the period commencing seven months following such
termination and ending twelve months after such termination, the Company will
continue to pay you your bi-weekly rate in effect at the time of termination and
provide and pay the Company's portion of your medical insurance, except that
such severance payments made to you during this period will be reduced by all
1099 and W-2 income earned or received by you during such period, including
income earned or received from consulting services or temporary employment, and
the Company's payments for your medical insurance will terminate when you have
such coverage through any new employer before the end of the twelve month period
following your termination. The Company will reconcile such payments with you
quarterly, and any additional payments owed to you by the Company, and any
payments owed to the Company by you, will be paid respectively within two weeks
following such reconciliation period. The Company will not be obligated to
continue any such payments to you under this paragraph 3(e) in the event you
materially breach the terms under the Confidentiality Agreement (as defined
below). Notwithstanding any termination of your employment, you will continue to
be bound by the provisions of the Confidentiality Agreement.

      (e) For the purposes of this Section 3, "Cause" shall include (i) your
conviction of a felony, either in connection with the performance of your
obligations to the Company or otherwise, which adversely affects your ability to
perform such obligations or materially adversely affects the business
activities, reputation, goodwill or image of the Company, (ii) your willful
disloyalty, deliberate dishonesty, breach of fiduciary duty, (iii) your breach
of the terms of this Agreement, or your failure or refusal to carry out any
material tasks assigned to you by the Company in accordance with the terms
hereof, which breach or failure continues for a period of more than thirty (30)
days after your receipt of written notice thereof from the Company, (iv) the
commission by you of any act of fraud, embezzlement or deliberate disregard of a
significant rule or policy of the Company known to you or contained in a policy
and procedure manual provided to you which results in material loss, damage or
injury to the Company, or (v) the material breach by you of any of the
provisions of the Confidentiality Agreement substantially in the form of
Attachment A to this letter.

      4. Benefits. You will be entitled as an employee of the Company to receive
such benefits as are generally provided its employees and executives and for
which you are eligible in accordance with Company policy as in effect from time
to time. The Company retains the right to change, add or cease any particular
benefit relating to its employees and executives generally. At this time, the
Company is offering a benefit program, consisting of medical, dental, life and

                                       2
<PAGE>

MEMORY PHARMACEUTICALS CORP.
James E. Barrett, Ph.D.

short/long term disability insurance, as well as a 401(k) retirement plan and
flexible spending plan. You will be eligible for eleven paid holidays, four
floating holidays and four (4) weeks paid vacation per year. You will accrue
additional vacation days in accordance with Company policy.

      5. Relocation Expenses. The Company will pay or reimburse you for all
reasonable out-of-pocket relocation and relocation-related expenses not to
exceed $100,000, including any Tax Payment (as defined below) and any Gross-up
Payment (as defined below), which may be billed directly to the Company or paid
by you and submitted for reimbursement, including, without limitation, the
following:

      (a) costs of services of moving companies (including packing,
transportation and relocation expenses, including the transportation of
automobiles);

      (b) costs associated with your search for a new residence (including,
without limitation, the costs of airfare, automobile rental, meals and hotel
accommodations for yourself and your immediate family);

      (c) commissions payable to brokers in connection with the sale of your
current residence;

      (d) costs attendant to the sale of your current residence and the purchase
of a new residence in the Northern New Jersey area (including, without
limitation, the costs of home inspections, survey, appraisal, title insurance,
transfer fees, attorneys' fees, accountants' fees, and closing costs);

      (e) loan origination fees (points) related to the purchase of your new
residence in an amount of up to three percent (3%) of the loan amount (and the
Company will provide assistance to you relating to the selection of a mortgage
lender that will pre-qualify you for a mortgage loan to purchase your new
residence);

      (f) costs associated with commuting from your current residence to the
Company's offices (including, without limitation, the costs of airfare,
automobile rental, meals and hotel accommodations for you) for a period of up to
six months, subject to extension upon our mutual agreement;

      (g) automobile rental charges prior to establishment of a permanent
residence in Northern New Jersey;

      (h) rent and other expenses associated with temporary housing for yourself
and your immediate family for a period of up to six months (which may include up
to two months after the purchase and closing of title on your new residence),
subject to extension upon our mutual agreement; and

      (i) payment of any duplicate mortgage loan payments and house expenses to
preclude your paying for your current residence and your new residence
concurrently.

      (j) All such payments will be subject to the Company receiving reasonably
acceptable documentation evidencing the incurring of such cost, expense or fee.
In the event that it should be determined that any payment shall be due by you
for taxes of any kind or nature relating to amounts paid to you or on your
behalf by the Company in connection with your relocation as provided above
("Taxes"), the Company will deliver to you a payment equal to the amount of such
Taxes (the "Tax Payment") plus an additional payment in an amount equal to any
additional taxes payable by you applicable to your receipt of the Tax Payment
(the "Gross-Up Payment"). All such payments are fully refundable to the Company
if you leave the Company within twelve months of your Start Date.

                                       3
<PAGE>

MEMORY PHARMACEUTICALS CORP.
James E. Barrett, Ph.D.

      6. Indemnification. The Company will indemnify you in connection with any
legal proceedings related to your actions on behalf of the Company, including
after your employment with the Company.

      7. Confidentiality. The Company considers the protection of its
confidential information and proprietary materials to be very important.
Therefore, as a condition of your employment, you and the Company will become
parties to a Confidentiality and Noncompetition Agreement substantially in the
form of Attachment A to this letter (the "Confidentiality Agreement").

      8. General.

      (a) This letter, together with the Confidentiality Agreement and the Stock
Option Agreement will constitute our entire agreement as to your employment by
the Company and will supersede any prior agreements or understandings, whether
in writing or oral.

      (b) This letter shall be subject to our review of a satisfactory medical
examination.

      (c) By signing this letter, you acknowledge that you have provided to the
Company information contained in your existing personnel files, together with
supportive information, attesting to the fact that you do not have nor are aware
of any non-competition or other similar agreement with your existing or prior
employer that would restrict or prohibit your becoming employed by the Company
or providing the services for the Company contemplated by this letter.

      (d) The law of the State of New Jersey shall govern this letter.

       You may accept this offer of employment and the terms thereof by signing
the enclosed additional copy of this letter and the Confidentiality Agreement
and the Stock Option Agreement, which execution will evidence your agreement
with the terms set forth herein and therein, and returning them to the Company.

      This offer of employment will expire on February 28, 2002, unless accepted
by you prior to such date. We look forward to you joining our team, and we
believe that your skills will compliment those of our existing management team,
and that you will make a significant contribution to Memory's growth. We look
forward to your prompt response to this offer letter.

Sincerely,

/s/ Joanne Leonard
------------------
Joanne Leonard
Senior Vice President
Chief Financial Officer
Memory Pharmaceuticals Corp.

ACCEPTED AND AGREED:

/s/ James Barrett
------------------
Date: 2/22/02


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<PAGE>

                                  ATTACHMENT A

                  CONFIDENTIALITY AND NONCOMPETITION AGREEMENT

                          MEMORY PHARMACEUTICALS CORP.

                                                                  April 16, 2002

James E. Barrett, Ph.D.
1231 River Road
Washington Crossing, PA  18977

Dear Jim:

      This letter is to confirm our understanding with respect to (i) your
agreement to protect and preserve information and property which is confidential
and proprietary to Memory Pharmaceuticals Corp. or its parent, subsidiaries or
affiliates, if any, (the "Company"), and (ii) your agreement not to compete with
the Company (the terms and conditions agreed to in this letter shall hereinafter
be referred to as the "Agreement"). In consideration of the mutual promises and
covenants contained in this Agreement, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby mutually
acknowledged, we have agreed as follows:

      1. Protected Information. You shall at all times, both during and after
any termination of this Agreement by either you or the Company, maintain in
confidence and shall not, without the prior written consent of the Company, use,
except in the course of performance of your duties for the Company, disclose or
give to others any fact or information which was disclosed to or developed by
you during the course of performing services for, or receiving training from,
the Company, and is not generally available to the public, including but not
limited to information and facts concerning business plans, customers, future
customers, suppliers, licensors, licensees, partners, investors, affiliates or
others, training methods and materials, financial information, sales prospects,
client lists, Inventions (as defined in Section 2), or any other scientific,
technical, trade or business secret or confidential or proprietary information
("Confidential Information") of the Company or of any third party provided to
you during the Term. In the event you are questioned by anyone not employed by
the Company or by an employee of or a consultant to the Company not authorized
to receive such information, in regard to any Confidential Information or any
other secret or confidential work of the Company, or concerning any fact or
circumstance relating thereto, or in the event that you become aware of the
unauthorized use of Confidential Information by any party, whether competitive
with the Company or not, you will promptly notify the Chief Executive Officer of
the Company.
<PAGE>
      You acknowledge and agree that a business will be deemed competitive with
the Company if it performs or plans to perform any of the services or
manufactures or sells or plans to manufacture or sell any of the products
planned, provided or offered by the Company or any products or services designed
to perform the same function or achieve the same results as the products or
services planned, provided or offered by the Company or if it performs or plans
to perform any other services and/or engages or plans to engage in the
development, production, manufacture, distribution or sale of any product
similar to any planned or actual services performed or products developed,
produced, manufactured, distributed or sold by the Company during the term of
your relationship with the Company.

      2. Ownership of Ideas, Copyrights and Patents.

            (a) Property of the Company. You agree that all ideas, discoveries,
creations, manuscripts and properties, innovations, improvements, know-how,
Inventions, designs, developments, apparatus, techniques, algorithms, software,
mask works, methods, and formulae (all of the foregoing being hereinafter
referred to as the "Inventions") which may be used in the business of the
Company, whether patentable, copyrightable, protectable as mask works or not,
which you may conceive, reduce to practice or develop alone or in conjunction
with another, or others, and whether at the request or upon the suggestion of
the Company, or otherwise, during the period in which you perform services for
or at the request of the Company (the "Term") and for a period of one (1) year
thereafter, shall be the sole and exclusive property of the Company, that you
shall promptly disclose any such Inventions to the Company both during and after
the Term, and that you shall not publish any such Inventions without the prior
written consent of the Company. You hereby assign to the Company all of your
right, title and interest in and to all of the foregoing. You further represent
and agree that to the best of your knowledge and belief none of the Inventions
will violate or infringe upon any right, patent, copyright, trademark or right
of privacy, or constitute libel or slander against or violate any other rights
of any person, firm or corporation, and that you will use your best efforts to
prevent any such violation. You also agree that you will neither disclose to the
Company or any of its employees nor use for their benefit any other person's or
company's trade secret or proprietary information, or information which you have
agreed not to disclose or use.

            (b) Cooperation. At any time during or after the Term, you agree
that you will fully cooperate with the Company, its attorneys and agents in the
preparation and filing of all papers and other documents as may be required to
perfect and protect the Company's rights in and to any of such Inventions,
including, but not limited to, joining in any proceeding to obtain and enforce
letters patent, copyrights, mask work registrations, trademarks or other legal
rights of the United States and of any and all other countries on such
Inventions, provided that the Company will bear the expense of such proceedings,
and that any patent, copyright, mask work registration, trademark or other legal
right so issued to you, personally, shall be assigned by you to the Company
without charge by you.

                                       2
<PAGE>
      3. Prohibited Competition.

            (a) Certain Acknowledgments and Agreements.

            (i) We have discussed, and you recognize and acknowledge the
      competitive and sometimes proprietary aspects of the business of the
      Company.

            (ii) You further acknowledge and agree that, during the course of
      your performing services for the Company, the Company will furnish,
      disclose or make available to you Confidential Information related to the
      Company's business and that the Company may provide you with unique and
      specialized training. You also acknowledge that such Confidential
      Information and such training have been developed and will be developed by
      the Company through the expenditure by the Company of substantial time,
      effort and money and that all such Confidential Information and training
      could be used by you to compete with the Company.

            (iii) You acknowledge that the Company will be engaged in the
      research, development or commercialization of agents to affect memory,
      learning, cognitive abilities or any directly related neurological and
      psychiatric functions (the "Field of Interest") and that any engagement by
      you, directly or indirectly, in the Field of Interest will be deemed
      competitive. You further acknowledge that the foregoing description is not
      exclusive and that the Company's products and services and planned
      products and services will change from time to time without notice to you
      and without formal amendment of this Agreement.

            (b) Covenants Not to Compete. During the Term and for a period of
one year following the expiration or termination of the Term, whether such
termination is voluntary or involuntary, you shall not, without the prior
written consent of the Company:

            (i) for yourself or on behalf of any other person or entity,
      directly or indirectly, either as principal, agent, employee, consultant,
      representative or in any other capacity, own, manage, operate or control,
      or be connected or employed by, or otherwise associate in any manner with,
      or engage in any business which is directly or indirectly competitive with
      the business of the Company within the United States (the "Restricted
      Territory"); or

            (ii) either individually or on behalf of or through any third party,
      solicit, divert or appropriate or attempt to solicit, divert or
      appropriate, for the purpose of competing with the Company or any present
      or future parent, subsidiary or other affiliate of the Company which is
      engaged in a similar business as the Company, any customers or patrons of
      the Company, or any prospective customers or patrons with respect to which
      the Company has developed or made a sales presentation (or similar
      offering of services), located within the Restricted Territory; or

            (iii) either individually or on behalf of or through any third
      party, directly or indirectly, solicit, entice or persuade or attempt to
      solicit, entice or persuade any other employees of or consultants to the
      Company or any present or future parent, subsidiary or

                                       3
<PAGE>
      affiliate of the Company to leave the services of the Company or any such
      parent, subsidiary or affiliate for any reason.

            (c) Reasonableness of Restrictions. You further recognize and
acknowledge that (i) the types of activities and employment which are prohibited
by this Section 1 are narrow and reasonable in relation to the skills which
represent your principal salable asset both to the Company and to your other
prospective employers, and (ii) the specific but broad geographical scope of the
provisions of this Section 1 is reasonable, legitimate and fair to you in light
of the Company's need to market its services and sell its products in a large
geographic area in order to have a sufficient customer base to make the
Company's business profitable and in light of the limited restrictions on the
type of employment prohibited herein compared to the types of employment for
which you are qualified to earn your livelihood.

            (d) Survival of Acknowledgments and Agreements. Your acknowledgments
and agreements set forth in this Section 1 shall survive the expiration or
termination of this Agreement and the termination of your employment with the
Company for any reason.

      4. Disclosure to Future Employers. You agree that you will provide, and
that the Company may similarly provide in its discretion, a copy of the
covenants contained in Sections 1, 2 and 3 of this Agreement to any business or
enterprise which you may directly, or indirectly, own, manage, operate, finance,
join, control or in which you participate in the ownership, management,
operation, financing, or control, or with which you may be connected as an
officer, director, employee, partner, principal, agent, representative,
consultant or otherwise.

      5. Records. Upon termination of your relationship with the Company, you
shall deliver to the Company any property of the Company which may be in your
possession including products, materials, memoranda, notes, records, reports, or
other documents or photocopies of the same, including without limitation any of
the foregoing recorded on any computer or any machine readable medium.

      6. No Conflicting Agreements. You have set forth on Exhibit 1 hereto all
computer software and/or Inventions made or conceived by you prior to the date
of this Agreement which you own an interest in and wish to exclude from this
Agreement and have listed on Exhibit 1 and attached copies hereto of any
agreements with other parties which may prevent your full compliance with the
terms stated herein. You hereby represent and warrant that, except as set forth
on Exhibit 1, you have no commitments or obligations inconsistent with this
Agreement and you hereby agree to indemnify and hold the Company harmless
against loss, damage, liability or expense arising from any claim based upon
circumstances alleged to be inconsistent with such representation and warranty.

      7. General.

            (a) Notices. All notices, requests, consents and other
communications hereunder shall be in writing, shall be addressed to the
receiving party's address set forth below or to such other address as a party
may designate by notice hereunder, and shall be either (i) delivered by hand,
(ii) made by telecopy or facsimile transmission, (iii) sent by overnight
courier, or (iv) sent by registered or certified mail, return receipt requested,
postage prepaid.

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<PAGE>
If to the Company:          Memory Pharmaceuticals Corp.
                            100 Philips Parkway
                            Montvale, New Jersey  07645
                            Attention:  Chief Financial Officer

With a copy to:             Sills Cummis Radin Tischman Epstein & Gross
                            One Riverfront Plaza
                            Newark, New Jersey  07102
                            Attn:  Ira A. Rosenberg, Esq.

If to Employee:             James E. Barrett, Ph.D.
                            1231 River Road
                            Washington Crossing, PA  18977

All notices, requests, consents and other communications hereunder shall be
deemed to have been given either (i) if by hand, at the time of the delivery
thereof to the receiving party at the address of such party set forth above,
(ii) if made by telecopy or facsimile transmission, at the time that receipt
thereof has been acknowledged by electronic confirmation or otherwise, (iii) if
sent by overnight courier, on the next business day following the day such
notice is delivered to the courier service, or (iv) if sent by registered or
certified mail, on the fifth business day following the day such mailing is
made.

            (b) Entire Agreement. This Agreement embodies the entire agreement
and understanding between the parties hereto with respect to the subject matter
hereof and supersedes all prior oral or written agreements and understandings
relating to the subject matter hereof. No statement, representation, warranty,
covenant or agreement of any kind not expressly set forth in this Agreement
shall affect, or be used to interpret, change or restrict, the express terms and
provisions of this Agreement.

            (c) Modifications and Amendments. The terms and provisions of this
Agreement may be modified or amended only by written agreement executed by the
parties hereto.

            (d) Waivers and Consents. The terms and provisions of this Agreement
may be waived, or consent for the departure therefrom granted, only by written
document executed by the party entitled to the benefits of such terms or
provisions. No such waiver or consent shall be deemed to be or shall constitute
a waiver or consent with respect to any other terms or provisions of this
Agreement, whether or not similar. Each such waiver or consent shall be
effective only in the specific instance and for the purpose for which it was
given, and shall not constitute a continuing waiver or consent.

            (e) Assignment. The Company may assign its rights and obligations
hereunder to any person or entity who succeeds to all or substantially all of
the Company's business or that aspect of the Company's business in which you are
principally involved. Your rights and obligations under this Agreement may not
be assigned by you without the prior written consent of the Company.

                                       5
<PAGE>
            (f) Benefit. All statements, representations, warranties, covenants
and agreements in this Agreement shall be binding on the parties hereto and
shall inure to the benefit of the respective successors and permitted assigns of
each party hereto. Nothing in this Agreement shall be construed to create any
rights or obligations except among the parties hereto, and no person or entity
shall be regarded as a third-party beneficiary of this Agreement.

            (g) Governing Law. This Agreement and the rights and obligations of
the parties hereunder shall be construed in accordance with and governed by the
law of the State of New Jersey, without giving effect to the conflict of law
principles thereof.

            (h) Jurisdiction and Service of Process. Any legal action or
proceeding with respect to this Agreement shall be brought in the courts of the
State of New Jersey or of the United States District Court for the District of
New Jersey. By execution and delivery of this Agreement, each of the parties
hereto accepts for itself and in respect of its property, generally and
unconditionally, the jurisdiction of the aforesaid courts. Each of the parties
hereto irrevocably consents to the service of process of any of the
aforementioned courts in any such action or proceeding by the mailing of copies
thereof by certified mail, postage prepaid, to the party at its address set
forth in Section 7(a) hereof.

            (i) Severability. The parties intend this Agreement to be enforced
as written. However, (i) if any portion or provision of this Agreement shall to
any extent be declared illegal or unenforceable by a duly authorized court
having jurisdiction, then the remainder of this Agreement, or the application of
such portion or provision in circumstances other than those as to which it is so
declared illegal or unenforceable, shall not be affected thereby, and each
portion and provision of this Agreement shall be valid and enforceable to the
fullest extent permitted by law; and (ii) if any provision, or part thereof, is
held to be unenforceable because of the duration of such provision or the
geographic area covered thereby, the Company and you agree that the court making
such determination shall have the power to reduce the duration and/or geographic
area of such provision, and/or to delete specific words and phrases
("blue-pencilling"), and in its reduced or blue-pencilled form such provision
shall then be enforceable and shall be enforced.

            (j) Interpretation. The parties hereto acknowledge and agree that
(i) the rule of construction to the effect that any ambiguities are resolved
against the drafting party, and (ii) the terms and provisions of this Agreement,
shall be construed fairly as to all parties hereto and not in favor of or
against a party, regardless of which party was generally responsible for the
preparation of this Agreement.

            (k) Headings and Captions. The headings and captions of the various
subdivisions of this Agreement are for convenience of reference only and shall
in no way modify, or affect the meaning or construction of any of the terms or
provisions hereof.

            (l) Injunctive Relief. You hereby expressly acknowledge that any
breach or threatened breach of any of the terms and/or conditions set forth in
Section 1, 2 or 3 of this Agreement will result in substantial, continuing and
irreparable injury to the Company. Therefore, you hereby agree that, in addition
to any other remedy that may be available to the Company, the Company shall be
entitled to injunctive or other equitable relief by a court of

                                       6
<PAGE>
appropriate jurisdiction in the event of any breach or threatened breach of the
terms of Section 1, 2 or 3 of this Agreement.

            (m) No Waiver of Rights, Powers and Remedies. No failure or delay by
a party hereto in exercising any right, power or remedy under this Agreement,
and no course of dealing between the parties hereto, shall operate as a waiver
of any such right, power or remedy of the party. No single or partial exercise
of any right, power or remedy under this Agreement by a party hereto, nor any
abandonment or discontinuance of steps to enforce any such right, power or
remedy, shall preclude such party from any other or further exercise thereof or
the exercise of any other right, power or remedy hereunder. The election of any
remedy by a party hereto shall not constitute a waiver of the right of such
party to pursue other available remedies. No notice to or demand on a party not
expressly required under this Agreement shall entitle the party receiving such
notice or demand to any other or further notice or demand in similar or other
circumstances or constitute a waiver of the rights of the party giving such
notice or demand to any other or further action in any circumstances without
such notice or demand.

            (n) Expenses. Each of the parties hereto shall pay its own fees and
expenses (including the fees of any attorneys, accountants, appraisers or others
engaged by such party) in connection with this Agreement, the transactions
contemplated and the enforcement hereof.

            (o) Counterparts. This Agreement may be executed in one or more
counterparts, and by different parties hereto on separate counterparts, each of
which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

      If the foregoing accurately sets forth our agreement, please so indicate
by signing and returning to us the enclosed copy of this letter.

                                          Very truly yours,

                                          MEMORY PHARMACEUTICALS CORP.


                                          By:       /s/ Joanne Leonard
                                               -------------------------------
                                          Name:     Joanne Leonard
                                          Title:    Chief Financial Officer

Accepted and Approved


  /s/ James E. Barrett
----------------------------
James E. Barrett, Ph.D.
Dated:  February 22, 2002

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