Conditional relations by monkeys: Reflexivity, symmetry, and transitivity

Two cynomolgous macaques categorized six colors into two groups of three after conditional discrimination training (zero-delay symbolic match-to-sample). The procedures resulted in the establishment of relations among the elements of each set-relations that were not specifically trained and that can be characterized by the properties of reflexivity, symmetry, and transitivity. Each set of colors was related to a characteristic pattern of responding: One response pattern involved temporal duration (press and hold the response keys); the second response pattern entailed repeated pressing and releasing of the response keys (fixed ratio 8). Six combinations of two colors were trained, three combinations from each set. After discriminative performance stabilized for each monkey, they were tested with 10 additional color combinations, all of which differed from the training combinations. The conditional relations established between test combinations can be characterized as stimulus equivalence. The training procedures were analogous to the procedure of using category names, and have implications for understanding the function of language in the formation of equivalence classes.     

An individual differences model for multiple regression

A model for multiple regression was developed which allows individual differences to emerge empirically. The model encompasses as special cases several of the previous attempts to improve psychological prediction by deviating from the usual linear multiple regression model. The model is tested with both artificial and real data. The results indicate that the model effectively reduces the variance of the error of prediction, and that the weights obtained are stable over different samples, and, to some extent, over different sets of predictors.This article is based upon a thesis submitted in partial fulfillment of the requirements for the doctoral degree at the University of Illinois. The author thanks Professor Ledyard R Tucker who served as committee chairman and offered considerable support and assistance.     

Adolescent victimization and associated suicidal and violent behaviors

This study examined the relationship between victimization and both suicidal and violent behaviors among 1,569 public high school students in New York State (excluding New York City). They had participated in the 1997 Youth Risk Behavior Survey and, based on their responses, were divided into four groups: no suicidal or violent behavior, suicidal behavior only, violent behavior only, and both suicidal and violent behaviors. Males reported significantly more victimization, less suicidal behavior, and more violent behavior compared with females. Logistic regression analyses indicated that all categories of suicidal/violent behaviors were more frequent among those who had been victimized compared with the nonvictimized, for both males and females. In addition, victimized males were over two times more likely than victimized females to report violent behavior only. Gender differences were not significant for victimized students in two groups, suicidal behavior only and both suicidal and violent behaviors, although the results were in the hypothesized direction for suicidal behavior (e.g., females were more prone to suicidal behavior only). It was concluded that identifying and treating the victims of violence should be an integral component of suicide prevention programs and interventions aimed at reducing interpersonal violence in schools.     

ROCs in recognition with and without identification

Receiver operating characteristics (ROCs) for the recognition of unidentified word fragments were analysed and compared with ROCs for the recognition of identified word fragments. In all conditions reported here, the z-transformed ROCs (z-ROCs) for recognition without identification were linear, with slopes near 1.0. In contrast, the z-ROCs for recognition with identification each had both a linear and a quadratic component, and a slope of substantially less than 1.0. Because the recognition of unidentified word fragments likely results from a familiarity process, the present study examined how well the effect can be explained by global matching variants of signal detection theory. Global matching models predict that memory should be better for strong items from a mixed list than for strong items from a pure list, and should be worse for weak items from a mixed list than for weak items from a pure list; however, only the latter pattern was shown for the recognition of unidentified items.     

Intuitively detecting what is hidden within a visual mask: Familiar–novel discrimination and threat detection for unidentified stimuli

Recognition without identification is the finding that, among recognition test items that go unidentified (as when a word is unidentified from a fragment), participants can discriminate those that were studied from those that were unstudied. In the present study, we extended this phenomenon to the more life-like situation of discriminating known from novel stimuli. Pictures of famous and nonfamous faces (Exp. 1), famous and nonfamous scenes (Exp. 2), and threatening and nonthreatening images (Exp. 3) were filtered in order to impede identification. As in list-learning recognition-without-identification paradigms, participants attempted to identify each image (e.g., whose face it was, what scene it was, or what was in the picture) and rated how familiar the image seemed on a scale of 0 (very unfamiliar) to 10 (very familiar). Among the unidentified stimuli, higher familiarity ratings were given to famous than to nonfamous faces (Exp. 1) and scenes (Exp. 2), and to threatening than to nonthreatening living/animate (but not to nonliving/nonanimate) images (Exp. 3). These findings suggest that even when a stimulus is too occluded to allow for conscious identification, enough information can be processed to allow a sense of familiarity or novelty with it, which appears also to be related to the sense of whether or not a living creature is a threat. That the sense of familiarity for unidentified stimuli may be related to threat detection for living or animate things suggests that it may be an adaptive aspect of human memory.     

Paradoxical effects of presentation modality on false memory.

Two experiments are reported in which the effects of presentation modality on false memory in recall and recognition are studied. False recall and recognition of critical targets are lower for non-presented items related to a study list when that study list is presented visually than when presented auditorily. This pattern of low levels of false memory for critical targets holds even when participants read the visually presented study items aloud. These results suggest that recollection of visual detail plays a role in the prevention of false memory. However, both the hit rates (true memory) and the false-alarm rates to weakly related distractors (non-critical targets) were higher for visual presentation than for auditory presentation, suggesting that more than one mechanism may underlie false recognition.     

A postdictive bias associated with déjà vu

Psychonomic Bulletin & Review - Recent research links reports of déjà vu – the feeling of having experienced something before despite knowing otherwise – with an illusory...     

Picture recognition without picture identification: a method for assessing the role of perceptual information in familiarity-based picture recognition

The present study examined the claim that unidentifiable test-pictures are processed and recognized on a perceptual, as opposed to a conceptual, level. Using an extension of the recognition without identification paradigm (e.g., Cleary, A. M. & Greene, R. L. (2000). Recognition without identification. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1063-1069; Peynircioglu, Z. F. (1990). A feeling-of-recognition without identification. Journal of Memory and Language, 29, 493-500), it was observed that when test-pictures were unidentifiable during a masked perceptual identification task, old-new discrimination occurred when the study-list consisted of pictures (Experiments 1-3), but not when the study-list consisted of picture names (Experiment 2) or when picture exemplars served as test-cues (Experiment 3). Results provide converging evidence that a study-test perceptual match is needed for the episodic recognition of unidentified test-pictures. Implications for the present paradigm as a tool for examining the role of perceptual information in recognition-familiarity are discussed.     

The role of autonomic arousal in feelings of familiarity

Subjective feelings of familiarity associated with a stimulus tend to be strongest when specific information about the previous encounter with the stimulus is difficult to retrieve (e.g., the butcher-on-the-bus phenomenon; [Mandler, G. (1980). Recognizing: The judgment of previous occurrence. Psychological Review, 87, 252-271.]). When a stimulus has been encountered previously and the circumstances of the encounter cannot be recollected, additional cognitive resources may be directed toward recollection processes; this resource allocation is accompanied by autonomic arousal [Dawson, M. E., Filion, D. L., & Schell, A. M. (1989). Is elicitation of the autonomic orienting response associated with allocation of processing resources?. Psychophysiology, 26, 560-572]. One easily measurable index of autonomic arousal is the skin conductance response (SCR). In the present study, participants studied lists of words and then gave recognition ratings to briefly displayed and masked studied and nonstudied test words while their SCRs were monitored. Results revealed a relationship between recognition ratings and the temporal characteristics of the SCR, supporting the idea that feelings of familiarity are indeed "feelings" in that they stem from autonomic arousal associated with cognitive resource allocation.     

Classroom observations of students with and without ADHD: Differences across types of engagement

The current study examined the behaviors related to academic engagement exhibited by students with ADHD during instruction in math and reading. A total of 155 students (92 ADHD, 63 recruited controls) in grades 1 through 4 participated in the study. Results revealed that students with ADHD exhibited statistically significant lower rates of academic engagement and higher rates of off-task behaviors than recruited controls and randomly selected peer comparisons. Specifically, students with ADHD exhibited statistically significant lower rates of passive academic engagement (PET) than recruited controls and peer comparisons; however no group differences were found with regard to active engaged time (AET). In addition, students with ADHD exhibited lower rates of AET than PET, a finding observed among both recruited controls and randomly selected peer comparisons. Implications for research and practice are discussed.