Introducing a new age-and-cognition-sensitive measurement for assessing spatial orientation using a landmark-less virtual reality navigational task

Age-related impairments during spatial navigation have been widely reported in egocentric and allocentric paradigms. However, the effect of age on more specific navigational components such as the ability to drive or update directional information has not received enough attention. In this study we investigated the effect of age on spatial updating of a visual target after a series of whole–body rotations and transitions using a novel landmark-less virtual reality (VR) environment. Moreover, a significant number of previous studies focused on measures susceptible to a general decline in motor skills such as the spent time navigating, the distance traversed. The current paper proposes a new compound spatial measure to assess navigational performance, examines its reliability and compares its power with those of the measures of duration and traversed distance in predicting participants' age and cognitive groups assessed by Montreal Cognitive Assessment (MoCA) scores. Using data from 319 adults (20–83 years), our results confirm the reliability, the age sensitivity, and the cognitive validity of the designed spatial measure as well as its superiority to the measures of duration and traversed distance in predicting age and MoCA score. In addition, the results show the significant effect of age cognitive status on spatial updating.     

Inconsistent Responding in a Criminal Forensic Setting: An Evaluation of the VRIN-r and TRIN-r Scales of the MMPI–2–RF

Criminal forensic evaluations are complicated by the risk that examinees will respond in an unreliable manner. Unreliable responding could occur due to lack of personal investment in the evaluation, severe mental illness, and low cognitive abilities. In this study, 31% of Minnesota Multiphasic Personality Inventory–2 Restructured Form (MMPI–2–RF; Ben-Porath & Tellegen, 2008/2011) profiles were invalid due to random or fixed-responding (T score ≥ 80 on the VRIN–r or TRIN–r scales) in a sample of pretrial criminal defendants evaluated in the context of treatment for competency restoration. Hierarchical regression models showed that symptom exaggeration variables, as measured by inconsistently reported psychiatric symptoms, contributed over and above education and intellectual functioning in their prediction of both random responding and fixed responding. Psychopathology variables, as measured by mood disturbance, better predicted fixed responding after controlling for estimates of cognitive abilities, but did not improve the prediction for random responding. These findings suggest that random responding and fixed responding are not only affected by education and intellectual functioning, but also by intentional exaggeration and aspects of psychopathology. Measures of intellectual functioning and effort and response style should be considered for administration in conjunction with self-report personality measures to rule out rival hypotheses of invalid profiles.     

Error discounting in probabilistic category learning

The assumption in some current theories of probabilistic categorization is that people gradually attenuate their learning in response to unavoidable error. However, existing evidence for this error discounting is sparse and open to alternative interpretations. We report 2 probabilistic-categorization experiments in which we investigated error discounting by shifting feedback probabilities to new values after different amounts of training. In both experiments, responding gradually became less responsive to errors, and learning was slowed for some time after the feedback shift. Both results were indicative of error discounting. Quantitative modeling of the data revealed that adding a mechanism for error discounting significantly improved the fits of an exemplar-based and a rule-based associative learning model, as well as of a recency-based model of categorization. We conclude that error discounting is an important component of probabilistic learning.     

Response-time tests of logical-rule models of categorization

A recent resurgence in logical-rule theories of categorization has motivated the development of a class of models that predict not only choice probabilities but also categorization response times (RTs; Fifi?, Little, & Nosofsky, 2010). The new models combine mental-architecture and random-walk approaches within an integrated framework and predict detailed RT-distribution data at the level of individual participants and individual stimuli. To date, however, tests of the models have been limited to validation tests in which participants were provided with explicit instructions to adopt particular processing strategies for implementing the rules. In the present research, we test conditions in which categories are learned via induction over training exemplars and in which participants are free to adopt whatever classification strategy they choose. In addition, we explore how variations in stimulus formats, involving either spatially separated or overlapping dimensions, influence processing modes in rule-based classification tasks. In conditions involving spatially separated dimensions, strong evidence is obtained for application of logical-rule strategies operating in a serial-self-terminating processing mode. In conditions involving spatially overlapping dimensions, preliminary evidence is obtained that a mixture of serial and parallel processing underlies the application of rule-based classification strategies. The logical-rule models fare considerably better than major extant alternative models in accounting for the categorization RTs.     

Category-contingent face adaptation for novel colour categories: Contingent effects are seen only after social or meaningful labelling

A face appears normal when it approximates the average of a population. Consequently, exposure to faces biases perceptions of subsequently viewed faces such that faces similar to those recently seen are perceived as more normal. Simultaneously inducing such aftereffects in opposite directions for two groups of faces indicates somewhat discrete representations for those groups. Here we examine how labelling influences the perception of category in faces differing in colour. We show category-contingent aftereffects following exposure to faces differing in eye spacing (wide versus narrow) for blue versus red faces when such groups are consistently labelled with socially meaningful labels (Extravert versus Introvert; Soldier versus Builder). Category-contingent aftereffects were not seen using identical methodology when labels were not meaningful or were absent. These data suggest that human representations of faces can be rapidly tuned to code for meaningful social categories and that such tuning requires both a label and an associated visual difference. Results highlight the flexibility of the cognitive visual system to discriminate categories even in adulthood.     

Features enhance the encoding of geometry

Successful navigation within an environment requires that the traveler establish the correct heading—a process referred to as orienting. Many studies have now shown that humans and non-human animals can use the geometric properties of an enclosure to orient. In the present study, two groups of Clark’s nutcrackers (Nucifraga columbiana) were trained, in a reference memory task, to find food hidden in one of four containers arranged to form a rectangular array. One group had unique objects placed next to each of the containers, whereas the second group had identical objects placed next to each of the containers. Here, I show for the first time that for the Clark’s nutcracker, the distinctive properties of these objects enhanced the encoding of the array’s geometry compared to the learning of geometric properties from an array of identical objects, which remained at chance after substantial amounts of training. Subsequent transformation tests showed that an object not associated with reward, but sharing the same geometric properties as the correct object, may have had inhibitory qualities. Furthermore, by systematically removing objects from the array, I show that although nutcrackers encoded the geometry of the array, they did not encode a complete featural representation of the objects within the array.     

Learning about environmental geometry: a flaw in Miller and Shettleworth's (2007) operant model

Many studies have examined how humans and other animals reestablish a sense of direction following disorientation in enclosed environments. Results showing that geometric shape of an enclosure is typically encoded, sometimes to the exclusion of featural cues, have led to suggestions that geometry might be encoded in a dedicated geometric module. Recently, Miller and Shettleworth (2007) proposed that the reorientation task be viewed as an operant task and they presented an associative operant model that appears to account for many empirical findings from reorientation studies. In this paper we show that, although Miller and Shettleworth's insights into the operant nature of the reorientation task may be sound, their mathematical model has a serious flaw. We present simulations to illustrate the implications of the flaw. We also propose that the output of a simple neural network, the perceptron, can be used to conduct operant learning within the reorientation task and can solve the problem in Miller and Shettleworth's model.     

Category contingent aftereffects for faces of different races, ages and species

Exposure to faces biases perceptions of subsequently viewed faces such that normality judgments of similar faces are increased. Simultaneously inducing such an aftereffect in opposite directions for two groups of faces might indicate discrete responding of the neural populations coding for those groups. Here we show such "category contingent" aftereffects following exposure to faces differing in eye-spacing (wide versus narrow) for European versus African faces, adult versus infant faces, and human versus monkey faces. As aftereffects reflect changes in responses of neural populations that code faces, our results may then suggest that functionally distinct neural populations code faces of different ages, races and species and that the human brain potentially contains discrete representations of these categories.     

Impulsivity and emotion dysregulation in Borderline Personality Disorder

This study examined the association of borderline personality disorder (BPD) and negative emotional states with impulsivity in the laboratory. Undergraduate participants who were high in BPD features (high-BPD; n = 39) and controls who were low in BPD features (low-BPD; n = 56) completed measures of negative emotional state before a laboratory measure of impulsivity--a passive avoidance learning task. Controlling for psychopathology, high-BPD participants committed a greater number of impulsive responses than did low-BPD participants. Negative emotional state moderated the effect of BPD on impulsive responses. High-BPD participants who were in a negative emotional state committed fewer impulsive responses than high-BPD participants who were low in negative emotional state. Fear, nervousness, and shame negatively correlated with impulsivity among high-BPD participants but not among low-BPD participants. In addition, high-BPD participants reported greater emotion dysregulation in a variety of domains, compared with low-BPD participants.