Unit bias. A new heuristic that helps explain the effect of portion size on food intake

ABSTRACT— People seem to think that a unit of some entity (with certain constraints) is the appropriate and optimal amount. We refer to this heuristic as unit bias. We illustrate unit bias by demonstrating large effects of unit segmentation, a form of portion control, on food intake. Thus, people choose, and presumably eat, much greater weights of Tootsie Rolls and pretzels when offered a large as opposed to a small unit size (and given the option of taking as many units as they choose at no monetary cost). Additionally, they consume substantially more M&M's when the candies are offered with a large as opposed to a small spoon (again with no limits as to the number of spoonfuls to be taken). We propose that unit bias explains why small portion sizes are effective in controlling consumption; in some cases, people served small portions would simply eat additional portions if it were not for unit bias. We argue that unit bias is a general feature in human choice and discuss possible origins of this bias, including consumption norms.     

Extending the Balloon Analogue Risk Task to Assess Naturalistic Risk Taking via a Mobile Platform

The Balloon Analogue Risk Task (BART) is a behavioral measure that is commonly used to assess risk taking propensity. The primary goal of the present study was to introduce a mobile version of the BART (mBART) that can be included within ambulatory assessment protocols to assess risk taking in daily life. Study 1 compared common BART indices (i.e., total money earned, adjusted average pumps, balloon explosions, and coefficient of variability [CV]) on a single administration of the laboratory BART on a computer and the mBART on a smartphone (n = 78). Results revealed generally consistent relationships between indices of risk taking propensity in both the laboratory BART and mBART. Study 2 administered the mBART as part of a 7-day ecological momentary assessment (EMA) protocol in a population of nondaily smokers (n = 51). Using multi-level models, results suggest that males have greater adjusted average pumps (p = .03), and that a participant’s average CV is negatively related to trait sensation seeking (p = .03) and positively associated with trait positive urgency (p = .04). There were within-person effects of study day (p = .05) and environment (p = .02) with respect to adjusted average pumps such that individuals took greater risks as the study progressed and were riskier when alone compared to with others. Inclusion of the mBART in EMA did not appear to significantly increase participant burden and demonstrated acceptable levels of compliance. These results offer initial evidence supporting the feasibility and utility of the mBART for ambulatory research designs.     

Assessment of mand selection for functional communication training packages

We evaluated the effects of training novel and existing mands during functional communication training (FCT) to decrease problem behavior for 2 children. A functional analysis (Phase 1) identified mands for FCT. Phase 2 used distinct stimulus conditions to train novel and existing mands. Phase 3 evaluated allocation of responding within a concurrent-schedules design. When reinforcement for either mand was concurrently available, the children used existing mands more than novel mands, but higher levels of problem behavior occurred with existing mands.     

Development of eye-movement control

Cognitive control of behavior continues to improve through adolescence in parallel with important brain maturational processes including synaptic pruning and myelination, which allow for efficient neuronal computations and the functional integration of widely distributed circuitries supporting top-down control of behavior. This is also a time when psychiatric disorders, such as schizophrenia and mood disorders, emerge reflecting a particularly vulnerability to impairments in development during adolescence. Oculomotor studies provide a unique neuroscientific approach to make precise associations between cognitive control and brain circuitry during development that can inform us of impaired systems in psychopathology. In this review, we first describe the development of pursuit, fixation, and visually-guided saccadic eye movements, which collectively indicate early maturation of basic sensorimotor processes supporting reflexive, exogenously-driven eye movements. We then describe the literature on the development of the cognitive control of eye movements as reflected in the ability to inhibit a prepotent eye movement in the antisaccade task, as well as making an eye movement guided by on-line spatial information in working memory in the oculomotor delayed response task. Results indicate that the ability to make eye movements in a voluntary fashion driven by endogenous plans shows a protracted development into adolescence. Characterizing the transition through adolescence to adult-level cognitive control of behavior can inform models aimed at understanding the neurodevelopmental basis of psychiatric disorders.     

Straightness as the main factor of the hErmann grid illusion

The generally accepted explanation of the Hermann grid illusion is Baumgartner's hypothesis that the illusory effect is generated by the response of retinal ganglion cells with concentric ON-OFF or OFF-ON receptive fields. To challenge this explanation, we have introduced some simple distortions to the grid lines which make the illusion disappear totally, while all preconditions of Baumgartner's hypothesis remain unchanged. To analyse the behaviour of the new versions of the grid, we carried out psychophysical experiments, in which we measured the distortion tolerance: the level of distortion at which the illusion disappears at a given type of distortion for a given subject. Statistical analysis has shown that the distortion tolerance is independent of grid-line width within a wide range, and of the type of distortion, except when one side of each line remains straight. We conclude that the main cause of the Hermann grid illusion is the straightness of the edges of the grid lines, and we propose a theory which explains why the illusory spots occur in the original Hermann grid and why they disappear in curved grids.     

Juvenile offenders' Miranda rights comprehension and self-reported likelihood of offering false confessions

This study examined whether age, IQ, and history of special education predicted Miranda rights comprehension and the self-reported tendency to falsely confess to a crime among 55 delinquent boys. The Miranda Rights Comprehension Instruments-II, a revised version of Grisso's Instruments for Assessing Understanding and Appreciation of Miranda Rights, were developed for this study and are described in detail in this article. Results revealed that age, IQ, and special education were related to comprehension of Miranda rights. When Miranda comprehension, age, and IQ were simultaneously tested as predictor variables of the self-reported likelihood of false confessions, only age served as an independent predictor. Research and policy implications of this study are presented, and recommendations for use of the original and revised instruments are reviewed.     

Psychosocial studies of surgically treated adults with unilateral total lip-maxilla-palate clefts

The psychological status of 51 adult subjects who had received surgery at the appropriate time for cleft lip-palate was investigated by questionnaire (Giessen test). In respect of social dominance this revealed a significant deviation towards social subordination among those with cleft lips and palates, which is explicable in terms of the lengthy and continuous treatment and appears to be of great importance as a defence and adaptation mechanism to those concerned. The inclusion of psychologists in the interdisciplinary care of cleft lip-palate patients is proposed.     

Adolescent Literacy Tutoring: Face-to-Face and Via Webcam Technology

The purpose of this research project was to examine the effectiveness of supervised literacy tutoring delivered by 25 secondary teacher candidates to middle and high school students via webcam technology and in person. The results stem from two semester-long studies of technology-delivered tutoring from a university to middle and high school settings. Findings support the effectiveness of delivering literacy tutoring components through 18 one-hour tutoring sessions using webcam technology with secondary teacher candidates as instructors. In addition, the data revealed that there was no significant difference in the literacy growth among those students who received tutoring in person or via webcam technology.