title: The effects of shadow presence on visual object-recognition

authors: Etheredge, Richard

abstract: Shadows provide valuable cues for many aspects of visual perception. This thesis discusses the definitions of cast and attached shadows, and the different types of shadow borders that exist. Eight experiments investigated whether the presence of shadows affects the speed or accuracy of human object recognition performance. Experiments 1 to 4 investigated the contributions of attached shadows to the recognition of novel objects, using a sequential-matching task modelled on that of Tarr, Kersten, and Biilthoff (1998). Their finding, of faster reaction times associated with the presence of shadows, was not replicated. Reaction times were not affected by the presence or absence of shadows. Across the four experiments, discrimination was either unaffected by shadow presence, or was at its highest when there were no shadows present. In Experiments 5 to 7, the effects of cast shadow presence on object recognition were assessed. Visual cues about the shape of the objects were constrained by manipulating the degree of foreshortening of both the objects, and the shadows cast by the objects. Shadow presence was only of benefit to recognition in highly constrained situations: where the objects were severely foreshortened, while their cast shadows were not. Experiment 8 assessed the affect upon recognition of manipulating shape-from-shading cues independently from shadow-border cues. Shadow presence was only beneficial where shading was negligible. It is suggested that shadow presence may only provide observable benefits to object recognition when other cues to an object's identity, such as bounding contour and shape-from-shading, are minimal. It appears that shadows have the potential to facilitate object recognition, but in most situations their presence will not produce any discriminatory, or reaction time, benefit.

text: The effects of shadow presence on visual object-recognition Shadows provide valuable cues for many aspects of visual perception. This thesis discusses the definitions of cast and attached shadows, and the different types of shadow borders that exist. Eight experiments investigated whether the presence of shadows affects the speed or accuracy of human object recognition performance. Experiments 1 to 4 investigated the contributions of attached shadows to the recognition of novel objects, using a sequential-matching task modelled on that of Tarr, Kersten, and Biilthoff (1998). Their finding, of faster reaction times associated with the presence of shadows, was not replicated. Reaction times were not affected by the presence or absence of shadows. Across the four experiments, discrimination was either unaffected by shadow presence, or was at its highest when there were no shadows present. In Experiments 5 to 7, the effects of cast shadow presence on object recognition were assessed. Visual cues about the shape of the objects were constrained by manipulating the degree of foreshortening of both the objects, and the shadows cast by the objects. Shadow presence was only of benefit to recognition in highly constrained situations: where the objects were severely foreshortened, while their cast shadows were not. Experiment 8 assessed the affect upon recognition of manipulating shape-from-shading cues independently from shadow-border cues. Shadow presence was only beneficial where shading was negligible. It is suggested that shadow presence may only provide observable benefits to object recognition when other cues to an object's identity, such as bounding contour and shape-from-shading, are minimal. It appears that shadows have the potential to facilitate object recognition, but in most situations their presence will not produce any discriminatory, or reaction time, benefit.

year: 2004

title: I-O Psychology in Aotearoa, New Zealand: A world away?

authors: O’Driscoll, Michael P.

subjects: Psychology

abstract: Industrial-organizational psychology has had a fairly long history in this country, dating back to around the 1920s (Jamieson & Paterson, 1993). To a large extent the field developed initially within universities, although the focus of I-O psychologists’ activities in this country has always been very applied. Inclusion of I-O psychology in university curricula originally started at the University of Canterbury (in the south island) and then Massey University (in the north island); now two other universities (University of Auckland and University of Waikato, both in the north island) also provide training programs in the field. There are about a dozen academics in psychology departments who would consider themselves to be I-O psychologists, and a small handful in management or HRM departments. Clearly the number of academics specializing in this field is very small. Although this poses challenges for the development of I-O psychology in Aotearoa New Zealand, at the same time it helps communication among us.

text: I-O Psychology in Aotearoa, New Zealand: A world away? Industrial-organizational psychology has had a fairly long history in this country, dating back to around the 1920s (Jamieson & Paterson, 1993). To a large extent the field developed initially within universities, although the focus of I-O psychologists’ activities in this country has always been very applied. Inclusion of I-O psychology in university curricula originally started at the University of Canterbury (in the south island) and then Massey University (in the north island); now two other universities (University of Auckland and University of Waikato, both in the north island) also provide training programs in the field. There are about a dozen academics in psychology departments who would consider themselves to be I-O psychologists, and a small handful in management or HRM departments. Clearly the number of academics specializing in this field is very small. Although this poses challenges for the development of I-O psychology in Aotearoa New Zealand, at the same time it helps communication among us.

year: 2007

title: Cultural justice, ethics and teaching

authors: Nairn, Ray

subjects: Maori

abstract: Te Tiriti o Waitangi provides both a basis for cultural justice in this society and an explication of the term; each of the articles identifying a significant aspect of cultural justice. First, there is the guarantee to the Maori signatories that the Crown would protect their independence - tino rangatiratanga, (also read as authority, autonomy or self-determination) [Article II]. In Article III Maori are promised that they will also have the “Rights and Privileges of British subjects”. Finally, in Article I, Maori cede to the Crown the right to govern, to make laws to protect all peoples from the evil consequences of lawlessness. The 1835 Declaration of Independence located legislative authority in the Wakaminenga (the gathered rangatira meeting in Congress); and in 1840, in the context of the Crown promises, Maori authorised the Crown to exercise that authority. For Maori Te Tiriti specifies cultural justice for interactions between Maori and settlers in the new society. Maori are guaranteed the right to self-determination (and the economic and social resources to make that practical) in their relations with New Zealand society. They are also entitled to the same opportunities as other citizens. The latter rights, embodied in local legislation and international covenants to which we are signatory, are not alternatives to the prior right of Maori people to their (cultural) autonomy. The exercise of legislative and organisational authority must be exercised in a manner consistent with the promises which clearly requires consultation and negotiation with Maori.

text: Cultural justice, ethics and teaching Te Tiriti o Waitangi provides both a basis for cultural justice in this society and an explication of the term; each of the articles identifying a significant aspect of cultural justice. First, there is the guarantee to the Maori signatories that the Crown would protect their independence - tino rangatiratanga, (also read as authority, autonomy or self-determination) [Article II]. In Article III Maori are promised that they will also have the “Rights and Privileges of British subjects”. Finally, in Article I, Maori cede to the Crown the right to govern, to make laws to protect all peoples from the evil consequences of lawlessness. The 1835 Declaration of Independence located legislative authority in the Wakaminenga (the gathered rangatira meeting in Congress); and in 1840, in the context of the Crown promises, Maori authorised the Crown to exercise that authority. For Maori Te Tiriti specifies cultural justice for interactions between Maori and settlers in the new society. Maori are guaranteed the right to self-determination (and the economic and social resources to make that practical) in their relations with New Zealand society. They are also entitled to the same opportunities as other citizens. The latter rights, embodied in local legislation and international covenants to which we are signatory, are not alternatives to the prior right of Maori people to their (cultural) autonomy. The exercise of legislative and organisational authority must be exercised in a manner consistent with the promises which clearly requires consultation and negotiation with Maori.

year: 1993