The limited capacity of humans to identify the components of taste mixtures and taste-odour mixtures

The capacity of humans to identify the components of taste mixtures and odour-taste mixtures was investigated in two experiments. Subjects were trained to identify the components presented alone and to use a 'yes/no' procedure to identify them in mixtures. All stimuli were presented with a retronasal (by mouth) technique. A maximum of three tastants were identified in both types of mixtures, only one tastant was identified in five-component taste mixtures, and no component was identified in four-component odour-taste mixtures. Importantly, in no instance was the olfactory stimulus identified in any mixture with tastes, including binary mixtures. Loss of identity of the odorant in binary and ternary mixtures may have been due to suppression as a consequence of temporal processing, or to the absence of an association between the odorant and tastants that had established an identifiable percept. In contrast, poor identification of the components of the quaternary odour-taste mixture and quinternary taste mixture is attributed to the limited capacity of working memory. Overall, the poorer ability to identify components in odour-taste mixtures than in taste mixtures indicates that interactions occurred between the two senses, challenging the proposal that odours and tastes are processed independently when present in complex chemosensory stimuli.     

Further evidence of a robust point-of-view bias in videotaped confessions

Four experiments were conducted to test possible limits on the previously demonstrated point-of-view bias in videotaped confessions. Study 1 showed that deliberation did not eliminate the bias. Study 2 showed that forewarning did not eliminate the bias. Study 3 showed that directing greater attention to the content of the confession did not eliminate the bias. Study 4 showed that using a lengthier, case-based confession also did not eliminate the bias. Taken together, this research clearly indicates that the legal system needs to be concerned with the potential for bias that exists in videotaped confessions. This research was supported by funds from the Ohio Board of Regents and the National Science Foundation (BNS-8911067 and SBR-9514966). We thank Kevin Apple, Kim Dudley, Kelly Kinnison, Melanie LaForce, Matthew Leafgren, Richelle Newvahner, Laurie Olsen, John Ray, Alicia Santuzzi, Jason Secondi, and Katie Strieker for their contributions to various aspects of the research. With the exception of Lassiter, order of authorship is alphabetical.     

Sadness and amusement reactivity differentially predict concurrent and prospective functioning in major depressive disorder

Depressed individuals often fail to react to emotionally significant stimuli. The significance of this pattern of emotional dysregulation in depression is poorly understood. In the present study, depressed and nondepressed participants viewed standardized neutral, sad, fear, and amusing films; and experiential, behavioral, and physiological responses to each film were assessed. Compared with nondepressed controls, depressed participants reported sadness and amusement in a flattened, context-insensitive manner. Those depressed participants who reported the least reactivity to the sad film exhibited the greatest concurrent impairment. Prospectively, the depressed participant who exhibited the least behavioral and heart rate reactivity to the amusing film were the least likely to recover from depression. Loss of the context-appropriate modulation of emotion in depression may reflect a core feature of emotion dysregulation in this disorder.     

A functional-analytic model of analogy: a relational frame analysis

The aim of this study was to explore a behavior-analytic model of analogical reasoning, defined as the discrimination of formal similarity via equivalence-equivalence responding. In Experiment 1, adult humans were trained and tested for the formation of four three-member equivalence relations: A1-B1-C1, A2-B2-C2, A3-B3-C3, and A4-B4-C4. The B and C stimuli were three-letter nonsense syllables, and the A stimulus was a colored shape. Subjects were then successfully tested for equivalence-equivalence responding (e.g., matching B1/C1 to B2/C2 rather than B3/C4). These tasks were designed such that equivalence-equivalence responding might allow subjects to discriminate a physical similarity between the relations involved. Some participants (color subjects) received only equivalence-equivalence tasks in which they might discriminate a color relation, whereas others (shape subjects) were given tasks in which they might discriminate a shape relation. A control group received both types of task. In a subsequent test for the discrimination of formal similarity, color subjects matched according to color, shape subjects matched according to shape, and the control group showed no consistent matching pattern. In Experiment 2, adult humans showed a transformation of the functions of a block-sorting task via this basic model of analogy. Empirical and conceptual issues related to these results are discussed.     

Introspection and cognitive brain mapping: from stimulus-response to script-report

Cognitive science has wholeheartedly embraced functional brain imaging, but introspective data are still eschewed to the extent that it runs against standard practice to engage in the systematic collection of introspective reports. However, in the case of executive processes associated with prefrontal cortex, imaging has made limited progress, whereas introspective methods have considerable unfulfilled potential. We argue for a re-evaluation of the standard 'cognitive mapping' paradigm, emphasizing the use of retrospective reports alongside behavioural and brain imaging techniques. Using all three sources of evidence can compensate for their individual limitations, and so triangulate on higher cognitive processes.     

Can the Edinburgh Risk of Repetition Scale Predict Repetition of Deliberate Self‐poisoning in an Australian Clinical Setting?

This study tested the ability of the Edinburgh Risk of Repetition Scale (ERRS) to identify patients at high risk for repeat deliberate self-poisoning (DSP). Consecutive DSP patients (N= 1,317) over a 3-year period were followed-up for 12 months. A statistically significant relationship between ERRS scores and repetition was observed; however, sensitivity and specificity were low. Logistic regression analysis revealed only "previous parasuicide" contributed significantly to repetition. The ERRS had limited value in identifying patients at high risk of repeat DSP in this clinical population.     

Varieties of preschool hyperactivity: multiple pathways from risk to disorder

In this paper we examine the characteristics of preschool attention deficit hyperactivity disorder (ADHD) from both mental disorder and developmental psychopathology points of view. The equivalence of preschool and school-aged hyperactivity as a behavioral dimension is highlighted together with the potential value of extending the use of the ADHD diagnostic category to the preschool period where these behaviours take an extreme and impairing form (assuming age appropriate diagnostic items and thresholds can be developed). At the same time, the importance of identifying pathways between risk and later ADHD is emphasized. Developmental discontinuity and heterogeneity are identified as major characteristics of these pathways. We argue that models that distinguish among different developmental types of early-emerging problems are needed. An illustrative taxonomy of four developmental pathways implicating preschool hyperactivity is presented to provide a framework for future research.