Automatic influence of arousal information on evaluative processing: Valence–arousal interactions in an affective Simon task

Previous research showed that evaluation speed is faster for negative stimuli that are high in arousal and for positive stimuli that are low in arousal. The present study investigated whether arousal and valence analogously interact in automatic stimulus evaluations, i.e., if stimulus valence is irrelevant for the task. One sample of participants switched randomly between an evaluation task and an affective Simon task that assessed stimulus evaluations indirectly. Another sample completed a pure Simon task. In all conditions, the influence of affective stimuli on task performance was enhanced when valence and arousal were congruent (i.e., high-arousing negative and low-arousing positive stimuli) than when both stimulus dimensions were incongruent (i.e., low-arousing negative and high-arousing positive stimuli). These findings suggest that evaluative implications of stimulus arousal and valence are automatically inferred even when stimulus evaluation is irrelevant for the task at hand.     

Negative priming and sequence learning

Three experiments used a novel sequence learning task, in which participants responded to changes in location of one visual stimulus whilst ignoring another. Experiment 1 demonstrated negative priming effects in this task, in that responses to individual sequence elements were disrupted when the attended stimulus (e.g., red asterisk) appeared at the location taken by the unattended stimulus (e.g., blue asterisk) on the immediately preceding trial. Experiments 2 and 3 found that negative priming effects extended beyond sensitivity to individual items, suggesting that people may be able to learn about sequential features of ignored events as well as about single events in isolation. The results are discussed in relation to current theories of negative priming.     

Evidence for perceptual learning in pigeons' recognition memory for pictures

In two experiments, pigeons were trained on a recognition memory task, which required them to refrain from responding to a picture seen earlier that day. They learned this discrimination without detectable reliance on cues relating to the sequence of positive and negative trials. In both experiments, performance was significantly better when the same restricted set of stimuli was used each day than when an entirely novel set of stimuli was used each day, and in the former case there was less evidence of any significant decline in performance with increases in the interval between first and second presentations of a stimulus. The results suggest a powerful perceptual learning effect.     

Positive and negative stimuli in relation to tennis players' reaction time

Research has indicated that negative and positive thoughts may affect sport performance. The purpose of this analogue study was to assess whether negative and positive stimuli influenced tennis performance similar to positive and negative thought. The reaction time (RT) of 40 competitive tennis players was measured during a timed response to a tennis ball rotating in a topspin, sidespin, or backspin direction on the computer screen. Immediately prior to the ball presentation, a phrase (accessory stimulus) was presented visually or aurally. The accessory stimulus provided either positive (e.g., 'nice shot') or negative information (e.g., 'bad shot') followed by the subject's name. Analysis showed a main effect only for the type of spin. The slowest RT occurred when responding to a tennis ball rotating in a backspin direction. A significant interaction was found for the sensory modality (audition vs vision) and polarity (positive vs negative) of the accessory stimulus. RT to negative stimuli was slowest when the accessory stimulus was presented aurally. The quickest RT to positive stimuli occurred when the accessory stimulus was presented aurally. These results indicated that negative and positive stimuli, when presented aurally, affected performance as positive and negative thoughts measured in other studies. Not measured was whether negative and positive stimuli actually produce the negative and positive thoughts, respectively, that have been reported to affect performance.     

Simple discrimination in stingless bees (Melipona quadrifasciata): Probing for select‐ and reject‐stimulus control

Simple and conditional discrimination training may produce various types of controlling relations. Responses may be controlled primarily by the positive stimulus (select–control relation) or by the negative stimulus (reject–control relation; the subject excludes the negative stimulus and chooses the positive). Bees learn to respond in simple and conditional discriminations. However, no study has searched for reject–control responding in Melipona bees. We trained Melipona quadrifasciata on a simple discrimination task (S+ vs. S‐; e.g., blue vs. yellow) and then probed for stimulus control with two types of probe trials, S+ versus a new stimulus (Select–control probes) and S‐ versus a new stimulus (Reject–control probes). For Group Different, a new‐stimulus color (e.g., white) was used in one type of probe and another color (e.g., black) was used in the other type. For Group Same, a single new‐stimulus color was used in both types of probes. On Select probes, the bees always preferred S+ to the new stimulus. On Reject probes, results were mixed. Depending on the colors used in training and probing, bees responded to both stimuli, and even preferred the S‐. The data suggest no control by the negative function of the S‐ and support the select‐stimulus control hypothesis of responding.     

Sequential effects in a two-choice serial reaction task

Twenty-four subjects performed a symbolic two-choice serial reaction task under four conditions. These were with a delay from previous response to onset of next stimulus of 100 millisec, 600 millisec., 2 sec., and a fourth condition of 2 sec. delay with verbal prediction of the next stimulus. A positive recency or repetition effect occurred at 100 millisec. delay where RTs to repeated stimuli were faster than RTs to alternate stimuli. At 600 millisec. this effect was still present, though much reduced. The 2 sec. delay gave a negative recency effect where RTs were slower to repeated than to alternate stimuli. This effect increased significantly with simultaneous prediction of the next stimulus. The verbal predictions themselves displayed negative recency. Run analysis of the four conditions revealed strking differences. These results emphasize the need for analysing the microstructure of choice RT situations and reveal deficiencies in present models.     

Incidental task sequence learning: perceptual rather than conceptual?

In four experiments we investigated whether incidental task sequence learning occurs when no instructional task cues are available (i.e. with univalent stimuli). We manipulated task sequence by presenting three simple binary-choice tasks (colour, form or letter case decisions) in regular repeated or random order. Participants were required to use the same two response keys for each of the tasks. We manipulated response sequence by ordering the stimuli so as to produce either a regular or a random order of left versus right-hand key presses. When sequencing in both, or either, separate stream (i.e. task sequence and/or response sequence) was changed to random, only those participants who had processed both sequences together showed evidence of sequence learning in terms of significant response time disruption (Experiments 1-3). This effect disappeared when the sequences were uncorrelated (Experiment 4). The results indicate that only the correlated integration of task sequence and response sequence produced a reliable incidental learning effect. As this effect depends on the predictable ordering of stimulus categories, it suggests that task sequence learning is perceptual rather than conceptual in nature.     

Individual response patterns in binary choice tasks with nondiscriminable stimuli

The present experiment sought to determine whether individual Ss tend to employ repeatedly the same response patterns in binary choice tasks containing nondiscriminable stimuli and, if so, whether the response sequences when used to construct stimulus sequences improve the performance of other choice tasks. Information and frequency analyses of the response sequences of 48 Ss showed moderate consistency of patterning within a light and within a tone task. Performance of a card task following the light and tone tasks was closely related to the task (light or tone) from which the stimulus sequence was obtained. The frequency analysis showed that repetition patterns were preferred by most Ss but at the expense of alternation responses. The presentation of reinforcement in the card task did not improve performance over that observed in the light and tone tasks.     

Response stereotypy without automaticity: Not quite involuntary attention in the pigeon

Previous research has shown that when pigeons are required to peck each of two keys four times in any order for reinforcement, stereotyped response sequences develop, though they are not required by the task. However, despite this stereotypy, sequences are not automatized. They require sufficient attention that sequence performance is disrupted by a concurrent, delayed matching-to-sample task. In the present experiments, pigeons were required to execute response sequences and delayed matching-to-sample concurrently. Experiment 1 showed that the matching task disrupts sequence performance even when the matching sample stimuli do not have to be processed concurrently with sequence execution. The presence of sample stimuli during sequence execution seems to command attention even if the sample stimuli are also available for processing when sequences are not being executed. Experiment 2 used the directed forgetting technique to show that pigeons do seem able to ignore sample stimuli if they are given information that tells them they will not be required to remember those stimuli later. Together, the experiments suggest attentional mechanisms in the pigeon that are not quite involuntary.     

Emotion processing facilitates working memory performance

The effect of emotional stimulus content on working memory performance has been investigated with conflicting results, as both emotion-dependent facilitation and impairments are reported in the literature. To clarify this issue, 52 adult participants performed a modified visual 2-back task with highly arousing positive stimuli (sexual scenes), highly arousing negative stimuli (violent death) and low-arousal neutral stimuli. Emotional stimulus processing was found to facilitate task performance relative to that of neutral stimuli, both in regards to response accuracy and reaction times. No emotion-dependent differences in false-alarm rates were found. These results indicate that emotional information can have a facilitating effect on working memory maintenance and processing of information.     

Emotion processing facilitates working memory performance

The effect of emotional stimulus content on working memory performance has been investigated with conflicting results, as both emotion-dependent facilitation and impairments are reported in the literature. To clarify this issue, 52 adult participants performed a modified visual 2-back task with highly arousing positive stimuli (sexual scenes), highly arousing negative stimuli (violent death) and low-arousal neutral stimuli. Emotional stimulus processing was found to facilitate task performance relative to that of neutral stimuli, both in regards to response accuracy and reaction times. No emotion-dependent differences in false-alarm rates were found. These results indicate that emotional information can have a facilitating effect on working memory maintenance and processing of information.     

Positive and negative affect produce opposing task-irrelevant stimulus preexposure effects

In three experiments, groups were exposed to either positive or negative affect video clips, after which they were presented with a series of task-irrelevant stimuli. In the subsequent test task, subjects were required to learn an association between the previously irrelevant stimulus and a consequence, and between a new stimulus and a consequence. Induced positive affect produced a latent inhibition effect (poorer evidence of learning with the previously irrelevant stimulus than with the novel stimulus). In opposition to this, induced negative affect resulted in better evidence of learning with a previously irrelevant stimulus than with a novel stimulus. In general, the opposing effects also were present in participants scoring high on self-report questionnaires of depression (Experiments 2 and 3). These unique findings were predicted and accounted for on the basis of two principles: (a) positive affect broadens the attentional field and negative affect contracts it; and (b) task-irrelevant stimuli are processed in two successive stages, the first encodes stimulus properties, and the second encodes stimulus relationships. The opposing influences of negative and positive mood on the processing of irrelevant stimuli have implications for the role of emotion in general theories of cognition, and possibly for resolving some of the inconsistent findings in research with schizophrenia patients.     

The Impact of Stimuli Color in Lexical Decision and Semantic Word Categorization Tasks

In two experiments, we examined the impact of color on cognitive performance by asking participants to categorize stimuli presented in three different colors: red, green, and gray (baseline). Participants were either asked to categorize the meaning of words as related to the concepts of “go” or “stop” (Experiment 1) or to indicate if a neutral verbal stimulus was a word or not (lexical decision task, Experiment 2). Overall, we observed performance facilitation in response to go stimuli presented in green (vs. red or gray) and performance inhibition in response to go stimuli presented in red. The opposite pattern was observed for stop‐related stimuli. Importantly, results also indicated that color might also be used to categorize neutral stimuli. Overall, these findings provide support to the green‐go and red‐stop color associations and test the potential functional autonomy acquired by these colors and the boundary conditions to their effects on stimuli categorization.     

Switching of response modalities

When participants perform a sequence of different tasks, it is assumed that the engagement in one task leads to the inhibition of the previous task. This inhibition persists and impairs performance when participants switch back to this (still inhibited) task after only one intermediate trial. Previous task-switching studies on this issue have defined different tasks at the level of stimulus categorization. In our experiments we used different response modalities to define tasks. Participants always used the same stimulus categorization (e.g., categorize a digit as odd vs. even), but had to give a vocal, finger, or foot response (A, B, or C). Our results showed a higher reaction time and error rate in ABA sequences than in CBA sequences, indicating n - 2 repetition cost as a marker for persisting task inhibition. We assume that different response modalities can define a task and are inhibited in a “task switch” in the same way as stimulus categories are inhibited.     

Control of adolescents' arbitrary matching-to-sample by positive and negative stimulus relations.

In Experiment 1, four developmentally delayed adolescents were taught an A-B matching-to-sample task with nonidentical stimuli: given Sample A1, select Comparison B1; given A2, select B2. During nonreinforced test trials, appropriate matching occurred when B stimuli appeared as samples and A stimuli as comparisons, i.e., the sample and comparison functions were symmetrical (B-A matching). During A-B or B-A matching test trials in which familiar samples and correct comparisons were presented along with novel comparisons, the subjects selected the correct comparisons. In tests with familiar samples and both incorrect and novel comparisons, subjects selected the novel comparisons, demonstrating control by both positive ("matching") and negative ("nonmatching") stimulus relations in A-B and B-A arrays. In Experiment 2, 12 developmentally delayed subjects were taught a two-stage arbitrary-matching task (e.g., A-B, C-B matching). Test sessions showed sample-comparison symmetry (e.g., B-A, B-C matching) and derived sample-comparison relations (e.g., A-C, C-A matching) for 11 subjects. These subjects also demonstrated control by positive and negative stimulus relations in the derived relations.     

Arousal,valence, and memory for detail

A common finding in the emotion‐memory literature is that memory is enhanced for positively arousing stimuli and negatively arousing stimuli relative to neutral stimuli. We tested the notion that post‐stimulus elaboration is responsible for these effects. Post‐stimulus elaboration refers to the process of thinking about an event (after its offset) more frequently or more in‐depth. We tested the hypothesis by presenting participants with 36 slides depicting events that varied in arousal (low and high) and valence (positive and negative). The opportunity for elaboration was manipulated by requiring participants, during the inter‐slide interval, to complete addition problems, simply view the addition problems, or view a blank slide. Cued recall memory was tested for central and background details. Based on the post‐stimulus elaboration hypothesis it was expected that the greatest memory decline would occur for the central details of negatively and positively arousing slides when participants were required to complete addition problems (i.e., a distractor task × arousal × detail interaction). Contrary to the hypothesis, we found that filling the inter‐slide interval with a distractor task decreased memory for negative stimuli compared to positive stimuli. This effect was independent of arousal. We also found that arousal increased central detail memory for positive and negative stimuli and background detail memory for positive stimuli but not for negative stimuli. This interaction was explained on the basis of pre‐attentive encoding and cue utilisation. It was concluded that in order to understand the complex relationship between emotion and memory, future studies should include, as a minimum, the variables of valence, arousal, and detail.     

两种任务下情绪韵律的加工进程

采用ERP技术分别考察了情绪判断和性别判断任务下情绪韵律的加工进程。结果显示：在175-275ms时间段,情绪韵律的加工受实验任务的调节,情绪判断任务下存在效价主效应及负性偏向,愤怒比高兴和中性诱发了更正的P2成分,而性别判断任务则无效价效应。在后期评价加工及反应准备阶段（400-800ms）,两种任务下,愤怒都比高兴和中性诱发了更正的晚成分。上述结果说明,不同情绪韵律的识别存在不同的认知机制,并在一定程度上会受加工任务的调节。     

认知负载对基于动机的情绪刺激加工的影响

结合数数任务和情绪flanker任务,探究不同认知负载条件下,高低趋近动机对情绪刺激加工的影响。结果发现：高负载组中,高趋近动机条件下,对积极目标刺激的反应显著快于消极目标刺激;低趋近动机条件下,对消极目标刺激的反应显著快于积极目标刺激。且高负载组中,各条件下的反应大多都显著慢于低负载组。低负载组中没有发现各条件之间的差异。结果表明,高负载条件下,高趋近动机促进了积极情绪刺激的加工,低趋近动机促进了消极情绪刺激的加工,高负载在一定程度上阻碍了情绪刺激的加工。     

认知负载对基于动机的情绪刺激加工的影响

结合数数任务和情绪flanker任务,探究不同认知负载条件下,高低趋近动机对情绪刺激加工的影响。结果发现：高负载组中,高趋近动机条件下,对积极目标刺激的反应显著快于消极目标刺激;低趋近动机条件下,对消极目标刺激的反应显著快于积极目标刺激。且高负载组中,各条件下的反应大多都显著慢于低负载组。低负载组中没有发现各条件之间的差异。结果表明,高负载条件下,高趋近动机促进了积极情绪刺激的加工,低趋近动机促进了消极情绪刺激的加工,高负载在一定程度上阻碍了情绪刺激的加工。     

The effect of comparative context on evaluative conditioning

Evaluative conditioning (EC) is a change in the evaluation of a stimulus after the stimulus co-occurred with affective stimuli. The present research examined whether EC of one stimulus depends also on the co-occurrence of another stimulus with positive or negative stimuli. We paired two target people with affective stimuli. We found that a person who appeared eight times with positive stimuli and eight times with negative stimuli was liked more when the other person appeared always (16 times) with negative stimuli than when the other person appeared always with positive stimuli. The manipulation did not change the US evaluation or the general standard on the value dimension of what a positive or negative stimulus is. We suggest that like other evaluative traits (e.g., evil, pretty) co-occurrence with affective stimuli is sensitive to temporary standards. The manipulation changed the standard of what co-occurrence with affective stimuli is considered positive versus negative.