t(14) = 1.33, p = .20, respectively. The steep slope of the probit function indicates good temporal acuity with a visual JND of 50 ms and an auditory JND of 59 ms. Case: F.D. Table 2 shows that F.D.’s single-target performance in the extinction task was close to ceiling at all three spatial configurations (mean = 97%). No effect of eccentricity upon performance was observed in either the visual or the auditory modality (p > .1). In contrast, extinction indices of < 1 revealed a significant reduction in accu- racy on dual- compared to single-target trials on visual and auditory trials (Figure 3, Panel 3A). This pattern is consistent with extinction in dual-target trials. With the exception of dual visual targets presented to the RH, F.D.’s performance was significantly worse than that of the controls at all locations (p < .001), decreasing monot- onically as the stimuli moved from the RH to the LH spatial configurations. Statistical comparisons of visual and auditory extinction indices at each location revealed no difference (p = .15) indicating comparable rates of extinction in both modalities. In the TOJ task, F.D. showed a general reduction of temporal acuity (Figure 3 Panel 3B). Goodness-of-fit for the observed data and estimated function were accepta- ble (see Table 3). The estimated mean fell outside the 95% CI around the control mean. F.D.’s visual PSS revealed a large bias away from the contralesional target. Visual targets presented on the left had to precede those on the right by an estimated 335 ms before their onsets were judged to be simultaneous. In contrast there was no evidence for an auditory spatiotemporal bias, with the auditory PSS close to that of the controls (14 ms). F.D.’s data, therefore, reveal a multimodal impairment in detecting simultaneous visual or auditory stimuli in the extinction task and a dissociation between visual and auditory judgments of temporal order. Importantly, this task by modality interaction occurs for stimuli presented to identical egocentric locations (i.e., ± 17°). Case: J.B. J.B.’s detection accuracy for single targets in the extinc- tion task was 100% (see Table 2). In the visual modality, extinction indices of unity demonstrated equally good performance for single- and dual-target trials at all loca- tions (Figure 3, Panel 4A). Auditory extinction indices for stimulus pairs presented to LH and CM revealed a slight decrement in dual- compared to single-target detection rates at these locations. Although responses to centrally presented auditory targets were reliably less accurate than those of controls (p < .05), visual and auditory performance was statistically consistent at this location (p > .2). This patient, therefore, demonstrates no reliable difference in performance across the two modalities. In the TOJ task, JND estimates in the visual (266 ms) and auditory (96 ms) tasks showed impoverished tempo- ral acuity compared to controls (Figure 3, Panel 4B). The NEGLECT IN VISION AND AUDITION 77 probit function on the visual task was particularly shal- low and had to be extrapolated beyond the SOA range in order to estimate the PSS (–544 ms). In the auditory task, the deviation of the PSS from zero was much smaller (–148 ms), but in the same direction (95% CIs around the visual and auditory PSS did not overlap revealing a reliable reduction in auditory compared to vis- ual spatiotemporal bias; see Table 3). Despite this, both visual and auditory PSS values fall outside the 95% CI around the control mean, revealing a multimodal spatio- temporal bias towards the ipsilesional stimulus. J.B’s data, therefore, reveal a multimodal impairment of tempo- ral order judgments for asynchronous visual and auditory stimuli in the absence of multimodal extinction for the same objects when these are simultaneously presented. DISCUSSION Research investigating the degree of correspondence between visual and auditory attentional bias has pro- duced mixed findings (e.g., De Renzi et al., 1989; Pavani et al., 2004; Pavani et al., 2003; Sinnett et al., 2007; Soroker et al., 1997; Zimmer et al., 2003). Inconsisten- cies in estimates of the degree of association between vis- ual and auditory neglect and extinction may in part be due to methodological factors: first, the use of tests that each afford different measurement sensitivity in each sensory modality, and, second, the grouping of data across individuals who vary in the site and extent of their causal lesion. The current study addresses these method- ological considerations by comparing visual and audi- tory neglect symptoms separately for two patients using tests designed explicitly to match spatial and temporal stimulus parameters in each modality. Despite a com- mon clinical diagnosis of visual neglect using pen and paper tests, both patients showed a unique pattern of impairment across two laboratory tasks commonly used to assess unimodal neglect and extinction. Our results reveal within-patient variability in the presence and degree of association between visual and auditory inattention as well as highlighting task-dependent variability in the way these are expressed. In the extinction task, F.D. showed reduced awareness of contralesional visual and auditory stimuli when a competing stimulus was present. This bias increased across a leftward spatial gradient that is consistent with gradient models of neglect and extinction (Cate & Behrmann, 2002; Kinsbourne, 1993; Pouget & Driver, 2000). This suggests the balance of competition between stimuli with a fixed angle of separation is mediated by both their relative and egocentric locations. The lack of any significant difference between extinction indices in each modality suggests that performance in this patient was affected by a common gradient of inattention. This is consistent with a multimodal attentional impairment for visual and auditory information represented within a common spatial metric (e.g., Frassinetti et al., 2002; Pavani et al., 2002, 2003). F.D.’s TOJ data, in contrast, reveal intact auditory performance in the presence of a visual deficit. In the auditory TOJ, F.D. performed