Selective attention to multidimensional auditory stimuli

Event-related brain potentials (ERPs) elicited by multidimensional auditory stimuli were recorded from the scalp in a selective-attention task. Subjects listened to tone pips varying orthogonally between two levels each of pitch, location, and duration and responded to longer duration target stimuli having specific values of pitch and location. The discriminability of the pitch and location attributes was varied between groups. By examining the ERPs to tones that shared pitch and/or locational cues with the designated target, we inferred interrelationships among the processing of these attributes. In all groups, stimuli that failed to match the target tone in an easily discriminable cue elicited only transitory ERP signs of selective processing. Tones sharing the "easy" but not the "hard" cue with the target elicited ERPs that indicated more extensive processing, but not as extensive as stimuli sharing both cues. In addition, reaction times and ERP latencies to the designated targets were not influenced by variations in the discriminability of pitch and location. This pattern of results is consistent with parallel, self-terminating models and holistic models of processing and contradicts models specifying either serial or exhaustive parallel processing of these dimensions. Both the parallel, self-terminating models and the holistic models provide a generalized mechanism for hierarchical stimulus selections that achieve an economy of processing, an underlying goal of classic, multiple-stage theories of selective attention.     

Facial reactions to emotional stimuli: Automatically controlled emotional responses

Based on a model in which the facial muscles can be both automatically/involuntarily controlled and voluntarily controlled by conscious processes, we explore whether spontaneously evoked facial reactions can be evaluated in terms of criteria for what characterises an automatic process. In three experiments subjects were instructed to not react with their facial muscles, or to react as quickly as possible by wrinkling the eyebrows (frowning) or elevating the cheeks (smiling) when exposed to pictures of negative or positive emotional stimuli, while EMG activity was measured from the corrugator supercilii and zygomatic major muscle regions. Consistent with the proposition that facial reactions are automatically controlled, the results showed that the corrugator muscle reaction was facilitated to negative stimuli and the zygomatic muscle reaction was facilitated to positive stimuli. The results further showed that, despite the fact that subjects were required to not react with their facial muscles at all, they could not avoid producing a facial reaction that corresponded to the negative and positive stimuli.     

Lateral eye-movement responses to visual stimuli

The association of left lateral eye-movement with emotionality or arousal of affect and of right lateral eye-movement with cognitive/interpretive operations and functions was investigated. Participants were junior and senior students enrolled in an undergraduate course in developmental psychology. There were 37 women and 13 men, ranging from 19 to 45 yr. of age. Using videotaped lateral eye-movements of 50 participants' responses to 15 visually presented stimuli (precategorized as neutral, emotional, or intellectual), content and statistical analyses supported the association between left lateral eye-movement and emotional arousal and between right lateral eye-movement and cognitive functions. Precategorized visual stimuli included items such as a ball (neutral), gun (emotional), and calculator (intellectual). The findings are congruent with existing lateral eye-movement literature and also are additive by using visual stimuli that do not require the explicit response or implicit processing of verbal questioning.     

Positive mood broadens visual attention to positive stimuli

In an attempt to investigate the impact of positive emotions on visual attention within the context of Fredrickson’s (1998) broaden-and-build model, eye tracking was used in two studies to measure visual attentional preferences of college students (n=58, n=26) to emotional pictures. Half of each sample experienced induced positive mood immediately before viewing slides of three similarly-valenced images, in varying central-peripheral arrays. Attentional breadth was determined by measuring the percentage viewing time to peripheral images as well as by the number of visual saccades participants made per slide. Consistent with Fredrickson’s theory, the first study showed that individuals induced into positive mood fixated more on peripheral stimuli than did control participants; however, this only held true for highly-valenced positive stimuli. Participants under induced positive mood also made more frequent saccades for slides of neutral and positive valence. A second study showed that these effects were not simply due to differences in emotional arousal between stimuli. Selective attentional broadening to positive stimuli may act both to facilitate later building of resources as well as to maintain current positive affective states.     

Selective attention to emotional faces following recovery from depression

This study was designed to examine attentional biases in the processing of emotional faces in currently and formerly depressed participants and healthy controls. Using a dot-probe task, the authors presented faces expressing happy or sad emotions paired with emotionally neutral faces. Whereas both currently and formerly depressed participants selectively attended to the sad faces, the control participants selectively avoided the sad faces and oriented toward the happy faces, a positive bias that was not observed for either of the depressed groups. These results indicate that attentional biases in the processing of emotional faces are evident even after individuals have recovered from a depressive episode. Implications of these findings for understanding the roles of cognitive and interpersonal functioning in depression are discussed.     

Sensation-seeking and preference for emotional visual stimuli

The Zuckerman Sensation-seeking Scale (SSS) was administered to 190 men and 197 women, who were also asked to choose 5 pictures out of a group of 21. Seven of these pictures had been rated as emotionally positive, 7 as emotionally neutral and 7 as emotionally negative. Choices of the high and low sensation-seeking groups were compared, and it was found that the high sensation-seekers had a stronger preference for the hegative stimuli than the lows, and the low sensation-seekers had a stronger preference for the positive stimuli than the highs. The results are discussed in terms of optimum level of arousal.     

Spatial attention to arousing emotional stimuli in younger and older adults

Motivation and Emotion - Most work on emotional attention in aging has focused exclusively on stimulus valence, with very few studies systematically examining how younger and older adults may...     

Emotional and autonomic responses to visual traumatic stimuli

A fine-grain analysis of autonomic responses are presented with the purpose of extending the conclusions from a previously published paper (Christianson & Nilsson, 1984) on emotional and memorial responses to traumatic visual stimuli. Control subjects were presented with a series of 18 slides of neutral faces, whereas the experimental subjects were presented with six slides of horrible facial injuries in positions 7–12, interspersed between six slides of neutral faces in the beginning, and six slides of neutral faces at the end of the series. The time course of heart rate (HR) and skin conductance (SC) during stimulus presentation was recorded. These data showed an initial pattern of increase in SC, but not in HR. This pattern was subsequently replaced by a combined increase in both SC and HR. The results are discrepant to previous work and are interpreted as effects of not informing the subjects about the gruesome slides to be presented.     

Prior cognitive activity implicitly modulates subsequent emotional responses to subliminally presented emotional stimuli

It has been reported that engagement in several kinds of cognitive activity can successfully inhibit unpleasant emotions. In this study, we tried to replicate the previous finding that cognitive activity can modulate subsequent psychological and physiological emotional processes and to investigate whether prior cognitive activity can attenuate implicit emotional processes triggered by subliminal emotional stimuli. Sixty students were randomly divided into three groups (cognitive task group, noncognitive task group, control group). The cognitive task group was asked to engage in an n-back task, while the control group was asked to stay calm. The noncognitive task group was asked to do a handgrip-squeezing task. All participants then engaged in a version of a subliminal affective priming task where they were unconsciously exposed to affectively negative pictures. The cognitive task group showed lower negative experiences after the subliminal affective priming task and a substantial reduction in their heart rate responses, as compared with the other groups. These results provide evidence that engagement in cognitive activity can attenuate emotional processes in an automatic and unconscious manner.     

Trade-offs in visual attention and the enhancement of memory specificity for positive and negative emotional stimuli

Emotional influences on memory can lead to trade-offs in memory for gist or detail and trade-offs in memory for central or peripheral aspects of an event. Attentional narrowing has often been proposed as a theoretical explanation for this pattern of findings with negative emotion. These trade-offs have been less extensively investigated with positive emotion. In three experiments, we investigate memory for specific visual details of positive and negative stimuli, examine central–peripheral trade-offs in memory, and assess the hypothesis that attentional narrowing contributes to emotional enhancement of memory specificity. We found that memory for details was enhanced by negative and positive emotion. Central–peripheral trade-offs were found in memory for negative emotional stimuli but not in memory for positive emotional stimuli. These trade-offs with negative emotion were associated with attentional narrowing at the time of encoding, as measured by eye movements. There were no attentional effects at the time of encoding found with positive emotional stimuli. Evidence was found for the attentional narrowing hypothesis of memory specificity and central–peripheral trade-offs in memory for negative emotional events. Alternative explanations for the positive emotional enhancement of memory specificity are required.     

Five-months-olds' attention and affective responses to still-faced emotional expressions

Mothers posed happy, sad, or neutral still-faces (SFs) between periods of normal interactions. Lowered infant attention and affect and increased grimacing occured during SF regardless of emotional expression posed during the SF period. Different static expressions elicited differential smiling; infants smiled slightly but significantly more to happy SFs. Greater differences occured with changes in contingent aspects of interactions.     

Selective visual attention and perceptual coherence

Conscious perception of the visual world depends on neural activity at all levels of the visual system from the retina to regions of parietal and frontal cortex. Neurons in early visual areas have small spatial receptive fields (RFs) and code basic image features; neurons in later areas have large RFs and code abstract features such as behavioral relevance. This hierarchical organization presents challenges to perception: objects compete when they are presented in a single RF, and component object features are coded by anatomically distributed neuronal activity. Recent research has shown that selective attention coordinates the activity of neurons to resolve competition and link distributed object representations. We refer to this ensemble activity as a "coherence field", and propose that voluntary shifts of attention are initiated by a transient control signal that "nudges" the visual system from one coherent state to another.     

Hydrocortisone infusion exerts dose- and sex-dependent effects on attention to emotional stimuli

Glucocorticoid administration has been shown to exert complex effects on cognitive and emotional processing. In the current study we investigated the effects of glucocorticoid administration on attention towards emotional words, using an Affective Go/No-go task on which healthy humans have shown an attentional bias towards positive as compared to negative words. Healthy volunteers received placebo and either low-dose (0.15 mg/kg) or high-dose (0.45 mg/kg) hydrocortisone intravenously during two separate visits in a double-blind, randomized design. Seventy-five minutes post-infusion, the subjects performed tests of attention (Rapid Visual Information Processing [RVIP]), spatial working memory (Spatial Span) and emotional processing (Affective Go/No-go task [AGNG]). On the attention task, performance was impaired under both hydrocortisone doses relative to placebo, though the effect on error rate was not significant after controlling for age; Spatial Span performance was unaffected by hydrocortisone administration. On the AGNG task, relative to the placebo condition the low-dose hydrocortisone infusion decreased response time to emotional words while high-dose hydrocortisone increased response time. In the females specifically, both high and low dose hydrocortisone administration attenuated the normal attentional bias toward positively valenced words. These data suggest that, in healthy women, the modulation of attention by the emotional salience of stimuli is influenced by glucocorticoid hormone concentrations.     

Heart-Rate responses (HRR) to lateralized visual stimuli

Direction of changes in heart-rate responses (HRR) were investigated in three separate experiments as a measure of differential cognitive and emotional specialization of the cerebral hemispheres. Visual stimuli were presented via the visual half-field technique in all three experiments. Slides with different contents were flashed for 200 msec on each trial either to the left or right of a center LED fixation point. The LED went on 5 seconds prior to slide onset. HR changes were scored as second-by-second deviations during 10 seconds after LED onset from pre-LED base line. In the first experiment it was hypothesized that emotionally relevant stimuli initially projected to only the right hemisphere would result in more anticipatory acceleration than when the same stimulus was initially projected to the left hemisphere. A picture of a snake and of a geometric figure were repeatedly briefly flashed to the right of the LED for half of the subjects, and to the left for the other half. There were 25 trials with an intertriai interval of 25–40 seconds. Results showed significant effects of deceleration as a function of the slide stimulus in all groups on seconds 5, 6, or 7 after onset of the center LED. Furthermore, an anticipatory acceleration was observed during the first trial-block on seconds 3 and 4 in the right hemisphere groups only with no differences between the neutral and emotional stimuli. In Experiments 2 and 3, a letter-string of six letters and a complex symmetric pattern were used as stimuli. These stimuli were chosen because previous research has clearly implicated the hemispheres to be differentially specialized in their ability to process verbal and visuo-spatial stimuli. The set-up was identical to Experiment 1, with the exception that differences in response to the two types of stimuli were evaluated on a within-subjects basis. The results from Experiments 2 and 3 showed stimulus-related deceleration, peaking on seconds 5–7 in all groups and an anticipatory acceleration peaking on seconds 3 and 4 in the right hemisphere groups, with decelerations during the corresponding seconds in the left hemisphere groups. The results are discussed in relation to recent findings by Walker and Sandman (1982) about the possibility of hemispheric specialization in psychologic influences on heart rate changes in response to environmental demands.     

An investigation of visual responses to brief stereoscopic stimuli

An analytic model of the temporal properties of visual responses to brief stimuli is described. The model is based on the notion that visual responses persist for some time after the occurrence of brief stimuli. The model is quantified from data on stereopsis obtained with alternating brief monocular presentations of disparate stimuli. The relevance of the analysis for the data of experiments using tachistiscopic techniques is discussed.     

Infant responses of ocular fixation to moving visual stimuli

Infants of 1, 2, and 3 months of age were presented with two checkerboard patterns, one stationary and the other moving in a horizontal oscillatory motion at one of eight rates. An observer who could see only the infant's head and eyes recorded, for each 30-sec trial, (a) the position of first fixation, (b) position of fixation at the end of each 5-sec interval, and (c) a final forced-choice judgment of the position of the moving stimulus. Results showed reliable differences in ocular behavior as a function of rate of stimulus motion for all three groups of infants.