Memory for affectively valenced and neutral stimuli in depression: Evidence from a novel matching task

Depressed persons have better memory for affectively negative than positive stimuli, a pattern generally not exhibited by non-depressed individuals. The mechanisms underlying this differential memory are not clear. In this study we examined memory for valenced and neutral stimuli in depressed and non-depressed individuals under conditions of relatively unconstrained encoding. We developed a novel task based on the game, Concentration, in which participants tried to match pairs of positive and negative words, and pairs of neutral words, hidden under squares in as few turns as possible. Whereas non-depressed participants selected and turned over positive squares more frequently than they did negative squares, depressed participants selected and turned over positive and negative squares equally often. Depressed participants also matched fewer positive word pairs within the first five minutes of the task than did non-depressed participants, and they exhibited poorer learning of positive words. Depressed and non-depressed participants did not differ in their matching of neutral words. These findings add to a growing literature indicating that depression is characterised by difficulties in the processing of positive stimuli.     

Competing stimulus assessments: A systematic review

The current review summarizes the literature on competing stimulus assessments (CSAs). CSAs are pretreatment assessments designed to systematically identify stimuli that reduce problem behavior (PB), ostensibly through reinforcer competition or substitution. We report on the participant characteristics, outcomes, and predictive validity of published CSAs that included (a) no-stimulus control trial(s), (b) test trials during which each stimulus was available singly and noncontingently, and (c) measurement of PB and stimulus engagement or contact. Results showed that CSAs have broad utility across a variety of topographies and functions of PB. In the majority of CSA applications for which extended analyses, or validations, were performed, stimuli shown to reduce PB during the CSA produced similar reductions during extended analysis. This was the case regardless of topography or function of PB, or whether the stimuli were assumed to be “matched” to the stimulation thought to be produced by PB. Implications for future research are discussed.     

Persistence of acquired behavioral control in the context of imprinting

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment.     

Laterality effects in the spinning dancer illusion: The viewing‐from‐above bias is only part of the story

The ‘silhouette illusion’, representing the silhouette of a female dancer pirouetting about her vertical axis, is a bistable stimulus created by Japanese web designer Nobuyuki Kayahara. Although the dancer can be perceived as spinning either clockwise or counterclockwise, the clockwise rotation is usually preferred. Troje and McAdam (i‐Perception, 2010, 1, 143) showed that this clockwise bias can be attributed to the tendency to assume a viewpoint from above rather than from below, given that the dancer is portrayed from a vantage point that is not perpendicular to the axis of rotation. Here, we tested whether another possible factor contributing to the observers’ interpretation of this bistable stimulus might be the tendency to perceive movements of the right rather than the left foot. We confirmed both the viewing‐from‐above bias and our hypothesis. The bias to perceive movements of the right leg might be a generalization to lower limbs of a perceptual frequency effect already observed for upper limbs. Such a perceptual and attentional bias towards the right hand/foot could account for the greater ability to predict the outcome of sport actions when observing right‐ rather than left‐limbed movements, and thus the left‐handers' and left‐footers' advantage observed in a variety of interactive sports.     

Evaluation of multiple schedules with naturally occurring and therapist‐arranged discriminative stimuli following functional communication training

Many studies have shown that (a) functional communication training (FCT) is effective for reducing problem behavior, and (b) multiple schedules can facilitate reinforcer schedule thinning during FCT. Most studies tha have used multiple schedules with FCT have included therapist‐arranged stimuli (e.g., colored cards) as the discriminative stimuli (S^Ds), but recently, researchers have evaluated similar multiple‐schedule training procedures with naturally occurring S^Ds (e.g., overt therapist behavior). The purposes of the current study were to compare the effects of arranged and naturally occurring S^Ds directly during (a) acquisition of discriminated functional communication responses (FCRs) and (b) generalization of discriminated FCRs when we introduced the multiple schedules in novel contexts in which the naturally occurring stimuli were either relatively easy or difficult to discriminate. Results showed that (a) 2 of 3 participants acquired discriminated responding of the FCR more rapidly with arranged than with naturally occurring stimuli, (b) 2 of 3 participants showed resurgence of problem behavior , and (c) 2 of 3 participants showed greater generalization of discriminated responding to novel contexts with arranged stimuli than with naturally occurring stimuli. We discuss these results relative to the conditions under which naturally occurring and arranged S^Ds may promote rapid and generalized treatment gains.     

Observing videos of a baby crying or smiling induces similar,but not identical,electroencephalographic responses in biological and adoptive mothers

It is well-known that adoptive mothers respond to cues from their babies in similar ways to biological mothers, and that cortical processing is critical for adequate motive–emotional maternal responses. This study used electroencephalographic activity (EEG) to characterize prefrontal, parietal and temporal functioning in biological mothers (BM), adoptive mothers (AM), and non-mothers (NM), while viewing videos of a baby smiling or crying. The BM presented higher absolute power (AP) in the delta and theta bands (associated with pleasant, positive emotional experiences) in the frontal and parietal areas under all conditions. In response to the smiling video, both types of mothers presented a lower AP in alpha1 in the three cortices (indicative of increased attention) and, mainly in temporal areas, a higher AP in the fast frequencies (beta and gamma, reflecting increased alertness to sensory stimuli and cognitive processing). This EEG pattern in the BM and AM could reflect the greater attention and, probably, the positive mood caused by the smiling video, showing that both are sensitive to these pleasant stimuli. When viewing the video of a baby crying, the AM had higher AP in the fast frequencies (temporal and parietal areas), indicating that they were more reactive to this unpleasant video, while the NM presented only a lower AP in alpha1 in all cortices, a finding that could be associated with the general activation induced by these unpleasant stimuli as a consequence of their lack of maternal experience. These findings should help improve our understanding of the neural mechanisms involved in the processing of sensorial stimuli that establish affective-emotional links during motherhood.     

Assessing emotional processing difficulties in normotensive individuals with high and isolated blood pressure elevations

This study examined the effect of sense modality (auditory/visual) on emotional dampening (reduced responsiveness to emotions with elevation in blood pressure). Fifty‐six normotensive participants were assessed on tasks requiring labelling and matching of emotions in faces and voices. Based on median split of systolic and diastolic blood pressures (SBP and DBP, respectively), participants were divided into low BP, high BP and isolated BP groups. On emotion‐labelling tasks, analysis revealed reduced emotion recognition in the high BP than the low BP group. On emotion‐matching tasks, reduced emotion recognition was noted in high and also isolated BP group as compared to low BP group for the task that required matching a visual target with one of the four auditory distractors. Our findings show for the first time that even isolated elevations in either SBP or DBP may result in emotional dampening. Furthermore, the study highlights that the emotional dampening effect generalises to explicit processing (labelling) of emotional information in both faces and voices—and that these effects tentatively occur during more pragmatic and covert (matching) emotion recognition processes too. These findings require replication in clinical hypertensives.     

Effects of auditory rhythm on movement accuracy in dance performance

The present study addresses the impact of the rhythmic complexity of music on the accuracy of dance performance. This study examined the effects of different levels of auditory syncopation on the execution of a dance sequence by trained dancers and exercisers (i.e., nondancers). It was hypothesized that nondancers would make more errors in synchronizing movements with moderately and highly syncopated rhythms while no performance degradation would manifest among trained dancers. Participants performed a dance sequence synchronized with three different rhythm tracks that were regular, moderately syncopated, and highly syncopated. We found significant performance degradation when comparing conditions of no syncopation vs. high syncopation for both trained dancers (p = .002) and nondancers (p = .001). Dancers and nondancers did not differ in how they managed to execute the task with increasing levels of syncopation (p = .384). The pattern of difference between trained dancers and nondancers was similar across the No Syncop and Highly Syncop conditions. The present findings may have marked implications for practitioners given that the tasks employed were analogous to those frequently observed in real-life dance settings.     

威胁性刺激注意偏向的时间进程

注意偏向各成分间关系及发生时间进程尚存争议。本研究以情绪图片为刺激,采用类别判断任务,通过眼动技术探讨正常个体对威胁性刺激注意偏向的时间进程。结果显示,(1)向左的首次眼跳概率高于向右,而潜伏期短于向右,存在左侧偏向;(2)注意回避发生在250ms以内,解除锁定困难发生在400ms之后;(3)注意偏向影响类别判断过程。结果表明,注意回避与左侧偏向在威胁性刺激注意偏向形成早期存在相互作用,且比解除锁定困难更早发生。     

Asymmetrical retention functions for sequences of light flashes or tone bursts in the rat

In Experiment 1, rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of sequences of magazine light flashes. The intertrial interval was illuminated by the houselight for Group Light, and it was dark for Group Dark. Retention functions exhibited a choose-many response bias when the delay interval was illuminated by the houselight in both groups, and no consistent response bias when the delay interval was dark. In Experiment 2, rats were trained to discriminate sample stimuli that consisted of sequences of tone bursts. During delay testing, a different tone (i.e., different frequency and location than the sample tone) was present or absent during the delay interval. The retention functions exhibited a significant choose-many bias when tone was present during the delay and a choose-few bias when tone was absent. Asymmetrical retention functions for tone burst and light flash sequences are due to the similarity between the stimulus conditions of the delay interval and the modality of the sequential event being discriminated. These results are consistent with an instructional ambiguity explanation of response biases in memory for number.