Recognition bias for critical faces in social phobia: a replication and extension

Studies using linguistic stimuli have provided little support for explicit memory biases among individuals with social phobia (SP). However, using facial stimuli rated on their criticalness, Lundh and Ost (1996) found that individuals with SP recognized more critical than accepting faces, whereas non-anxious controls tended to show the opposite pattern. Since the publication of Lundh and Ost's findings, additional studies using a variety of facial stimuli have produced inconsistent findings (J. Anxiety Disord. 14 (2000) 501; Behav. Res. Ther. 39 (2001) 967). Unfortunately, these inconsistencies are difficult to reconcile given great variation in methods and stimuli. Therefore, we designed a study to replicate and extend the work of Lundh and Ost (Behav. Res. Ther. 34 (1996) 787). Similar to Lundh and Ost, individuals with SP identified a significantly higher proportion of old critical faces as old than did non-anxious controls. Further, extending the work of Lundh and Ost, signal detection analyses revealed group differences on response bias according to face type. Specifically, controls showed a response bias towards indicating that accepting faces were previously seen, whereas individuals with SP did not. Finally, signal detection analyses failed to reveal group differences in the accuracy of memory.     

Discriminability and sensitivity to reinforcer magnitude in a detection task

Three pigeons discriminated between two sample stimuli (intensities of red light). The difficulty of the discrimination was varied over four levels. At each level, the relative reinforcer magnitude for the two correct responses was varied across conditions, and the reinforcer rates were equal. Within levels, discriminability between the sample stimuli did not change systematically as reinforcer magnitude varied. Across levels, the sensitivity of behavior to changes in the reinforcer-magnitude ratio decreased as the discriminability between the sample stimuli increased. Subsequent analysis showed that this relation was limited to performance following only one of the sample stimuli, the dim red light that remained constant across all conditions. Extant behavioral models of signal detection cannot easily accommodate these results.     

Use or misuse of the selection task? Rejoinder to Fiddick,Cosmides, and Tooby

Sperber, Cara, and Girotto (Cognition 52 (1995) 3) argued that, in Wason's selection task, relevance-guided comprehension processes tend to determine participants' performance and pre-empt the use of other inferential capacities. Because of this, the value of the selection task as a tool for studying human inference has been grossly overestimated. Fiddick, Cosmides, and Tooby (Cognition 77 (2000) 1) argued against Sperber et al. that specialized inferential mechanisms, in particular the "social contract algorithm" hypothesized by Cosmides (Cognition 31 (1989) 187), pre-empt more general comprehension abilities, making the selection task a useful tool after all. We rebut this argument. We argue and illustrate with two new experiments, that Fiddick et al. mix the true Wason selection task with a trivially simple categorization task superficially similar to the Wason task, yielding methodologically flawed evidence. We conclude that the extensive use of various kinds of selection tasks in the psychology of reasoning has been quite counter-productive and should be discontinued.     

Toward a unified theory of decision criterion learning in perceptual categorization

Optimal decision criterion placement maximizes expected reward and requires sensitivity to the category base rates (prior probabilities) and payoffs (costs and benefits of incorrect and correct responding). When base rates are unequal, human decision criterion is nearly optimal, but when payoffs are unequal, suboptimal decision criterion placement is observed, even when the optimal decision criterion is identical in both cases. A series of studies are reviewed that examine the generality of this finding, and a unified theory of decision criterion learning is described (Maddox & Dodd, 2001). The theory assumes that two critical mechanisms operate in decision criterion learning. One mechanism involves competition between reward and accuracy maximization: The observer attempts to maximize reward, as instructed, but also places some importance on accuracy maximization. The second mechanism involves a flat-maxima hypothesis that assumes that the observer's estimate of the reward-maximizing decision criterion is determined from the steepness of the objective reward function that relates expected reward to decision criterion placement. Experiments used to develop and test the theory require each observer to complete a large number of trials and to participate in all conditions of the experiment. This provides maximal control over the reinforcement history of the observer and allows a focus on individual behavioral profiles. The theory is applied to decision criterion learning problems that examine category discriminability, payoff matrix multiplication and addition effects, the optimal classifier's independence assumption, and different types of trial-by-trial feedback. In every case the theory provides a good account of the data, and, most important, provides useful insights into the psychological processes involved in decision criterion learning.     

Ingroup and outgroup differences in face detection

Humans show improved recognition for faces from their own social group relative to faces from another social group. Yet before faces can be recognized, they must first be detected in the visual field. Here, we tested whether humans also show an ingroup bias at the earliest stage of face processing – the point at which the presence of a face is first detected. To this end, we measured viewers' ability to detect ingroup (Black and White) and outgroup faces (Asian, Black, and White) in everyday scenes. Ingroup faces were detected with greater speed and accuracy relative to outgroup faces (Experiment 1). Removing face hue impaired detection generally, but the ingroup detection advantage was undiminished (Experiment 2). This same pattern was replicated by a detection algorithm using face templates derived from human data (Experiment 3). These findings demonstrate that the established ingroup bias in face processing can extend to the early process of detection. This effect is ‘colour blind’, in the sense that group membership effects are independent of general effects of image hue. Moreover, it can be captured by tuning visual templates to reflect the statistics of observers' social experience. We conclude that group bias in face detection is both a visual and a social phenomenon.     

Juveniles and adults differ in their beliefs about cues to deception and strategies during a hypothetical police interview

Police officers are often trained to use the Behavior Analysis Interview (BAI) to detect deceit, but it is based on faulty indicators of lying that may be especially problematic for juveniles due to developmental immaturities. Juveniles, young adults, and adults were assigned to guilt or innocence conditions, read a criminal scenario, and self-reported their likelihood of providing truthful and deceitful responses during a hypothetical BAI. All participants indicated they would give more truthful than deceptive responses. Guilty participants reported more use of strategies to appear innocent, while innocent participants said they would behave naturally. Juveniles were more likely to choose deceitful responses and say they would use strategies to appear innocent during a police interview but endorsed fewer stereotypical cues of deception compared to adults. Juveniles may not recognize how certain behaviors could be seen as cues to deception, which could put them at risk of being misidentified as guilty.     

Visual span of detection and recognition of a kanji character embedded in a horizontal row of random hiragana characters

Two experiments were conducted to determine the visual span of detection and recognition of the kanji character embedded in a horizontal row of random hiragana characters. An independent variable was the visual complexity of the kanji characters: simple and complex. In Experiment 1, visual spans of detection were determined by a staircase method. Values of visual spans were more than 15 character spaces for the complex kanji characters, and ranged from 4 to 10 character spaces (mean 7.6) for the simple kanji characters. In Experiment 2, visual spans of recognition were determined by an ascending series of limits method. Values of visual spans ranged from 0 to 4 character spaces (mean 2.3) for the complex kanji characters and from 3 to 7 character spaces (mean 4.8) for the simple kanji characters. These results are discussed in relation to reading of Japanese kanji-kana mixed texts.     

Recognition memory in older adults: adjustment to changing contingencies.

Four older and 4 younger men were given extended exposure to a continuous-recognition memory procedure. Experimental variables included the type of stimulus (alphanumeric strings, words, or sentences), the intervals separating repeated items, gains and losses for correct and incorrect recognitions, and the extent of practice with the memory task. Signal detection analyses indicated that the older men generally were less accurate (sensitivity), particularly when the stimuli were strings, but that age differences decreased with practice. Under conditions in which the payoff matrix was neutral, the older and younger men showed equivalent rates of hits and false alarms (bias). Alteration of the matrix to require more liberal or more conservative patterns of recognition responding led to corresponding changes for men of both ages. Adjustments by the older men, however, were not as close to the bias values called for by the new matrices.     

Conjoint control of performance in conditional discriminations by successive and simultaneous stimuli.

In a conditional discrimination, reinforcement of pigeons' responses to pairs of simultaneously presented wavelength stimuli depended on the orientation of white lines superimposed on the wavelengths. Over different conditions in Experiment 1, three wavelength differences were combined with two differences between successively presented line orientations. Measures of stimulus discriminability increased with increases in the difference between both orientation and wavelength stimuli. Conditional-discrimination performance was thus conjointly determined by stimulus disparity in the successive and simultaneous discriminations. In Experiment 2, ratios of rates of reinforcement contingent upon the two categories of correct responses were varied over several conditions for difficult and easy discriminations. Ratios of responses to wavelength pairs were sensitive to variations in the reinforcement ratio to a greater extent for the more difficult orientation discrimination than for the easier orientation discrimination. Performance in the conditional discrimination was therefore determined by the interacting effects of stimulus disparity and the relative rates of reinforcement contingent upon the two correct choices. It was concluded that the effect of temporally distant reinforcement on behavior in a prevailing schedule component is attenuated to an extent that depends on similarity of stimuli that delineate the successive components.     

Resources masquerading as slots: Flexible allocation of visual working memory

Whether the capacity of visual working memory is better characterized by an item-based or a resource-based account continues to be keenly debated. Here, we propose that visual working memory is a flexible resource that is sometimes deployed in a slot-like manner. We develop a computational model that can either encode all items in a memory set, or encode only a subset of those items. A fixed-capacity mnemonic resource is divided among the items in memory. When fewer items are encoded, they are each remembered with higher fidelity, but at the cost of having to rely on an explicit guessing process when probed about an item that is not in memory. We use the new model to test the prediction that participants will more often encode the entire set of items when the demands on memory are predictable.