scholarly journals 'Pseudoextinction': Asymmetries in simultaneous attentional selection

2016 ◽  
Author(s):  
Patrick T. Goodbourn ◽  
Alex O. Holcombe ◽  
Charlie Ludowici

We report robust visual field asymmetries associated with selectingsimultaneous targets. One letter embedded in a rapid serial visual presentation(RSVP) of letters was encircled by a white ring, cueing it as the target to report. In some conditions, 2 RSVP streams were presented concurrently, and targets appearedsimultaneously in both. When only 1 stream was cued, performance was similarregardless of whether it was in the left or right visual field. Cueing 2 streams barelyaffected performance in the left stream, but performance in the right stream sufferedmarkedly. We term this phenomenon pseudoextinction, by analogy to pseudoneglectwhereby observers bisect lines to the left of center. Such attentional asymmetries areoften believed to originate from a processing imbalance between the 2 cerebralhemispheres. But pseudoextinction also occurred with vertically arrayed streams, withhigher efficacy in the superior than in the inferior stream. Mixture modeling of errorsindicated that pseudoextinction did not affect the temporal precision or latency ofselection episodes; rather, only the efficacy of selection suffered. These findings leadus to suggest that pseudoextinction arises because perceptual traces are activatedsimultaneously in a visual buffer but must be tokenized serially. Observers succeed inselecting simultaneous targets because trace activation occurs in parallel. However,observers often fail to report both targets because tokenization proceeds serially:While 1 target is being tokenized, the other’s trace may decay below the activationlevel necessary for tokenization.

2017 ◽  
Vol 29 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Kamila Śmigasiewicz ◽  
Gabriel Sami Hasan ◽  
Rolf Verleger

In dynamically changing environments, spatial attention is not equally distributed across the visual field. For instance, when two streams of stimuli are presented left and right, the second target (T2) is better identified in the left visual field (LVF) than in the right visual field (RVF). Recently, it has been shown that this bias is related to weaker stimulus-driven orienting of attention toward the RVF: The RVF disadvantage was reduced with salient task-irrelevant valid cues and increased with invalid cues. Here we studied if also endogenous orienting of attention may compensate for this unequal distribution of stimulus-driven attention. Explicit information was provided about the location of T1 and T2. Effectiveness of the cue manipulation was confirmed by EEG measures: decreasing alpha power before stream onset with informative cues, earlier latencies of potentials evoked by T1-preceding distractors at the right than at the left hemisphere when T1 was cued left, and decreasing T1- and T2-evoked N2pc amplitudes with informative cues. Importantly, informative cues reduced (though did not completely abolish) the LVF advantage, indicated by improved identification of right T2, and reflected by earlier N2pc latency evoked by right T2 and larger decrease in alpha power after cues indicating right T2. Overall, these results suggest that endogenously driven attention facilitates stimulus-driven orienting of attention toward the RVF, thereby partially overcoming the basic LVF bias in spatial attention.


2005 ◽  
Vol 11 (3) ◽  
pp. 263-272 ◽  
Author(s):  
ANTJE HOLLÄNDER ◽  
MARKUS HAUSMANN ◽  
JEFF P. HAMM ◽  
MICHAEL C. CORBALLIS

The present study examines differences in functional cerebral asymmetries modulated by gonadal steroid hormones during the menstrual cycle in women. Twenty-one right-handed women with regular menstrual cycles performed a double-stream rapid serial visual presentation (RSVP) task, with one stream in each visual field, during the low steroid menses and the high steroid midluteal phase. They were required to detect a target item, and then a probe item, each of which could appear in either stream. If the probe item appeared 200 ms after the target, detection of the probe was impaired—a phenomenon known as the “attentional blink.” This occurred in both streams in the midluteal phase, but only in the right visual field during menses. Thus low steroid levels appeared to restrict the attentional blink to the left hemisphere, while high levels of estradiol and progesterone in the midluteal phase appeared to reduce functional asymmetries by selectively increasing the attentional blink in the right hemisphere. This effect appears to be mediated by estradiol rather than progesterone, and it is compatible with the assumption of a hormone-related suppression of right hemisphere functions during the midluteal phase. (JINS, 2005,11, 263–272.)


2007 ◽  
Vol 19 (3) ◽  
pp. 445-454 ◽  
Author(s):  
Marco Tamietto ◽  
Giuliano Geminiani ◽  
Rosanna Genero ◽  
Beatrice de Gelder

Survival depends to some extent on the ability to detect salient signals and prepare an appropriate response even when attention is engaged elsewhere. Fearful body language is a salient signal of imminent danger, easily observable from a distance and indicating to the observer which adaptive action to prepare for. Here we investigated for the first time whether fearful body language modulates the spatial distribution of attention and enhances visual awareness in neurological patients with severe attentional disorders. Patients with visual extinction and hemispatial neglect following right parietal injury have a rightward attentional bias accompanied by loss of awareness for contralesional left stimuli, especially when competing stimuli appear to the right. Three such patients were tested with pictures of fearful, happy, and neutral bodily expressions briefly presented either unilaterally in the left or right visual field, or to both fields simultaneously. On bilateral trials, unattended and task-irrelevant fearful bodily expressions modulated attentional selection and visual awareness. Fearful bodily expressions presented in the contralesional unattended visual field simultaneously with neutral bodies in the ipsilesional field were detected more often than left-side neutral or happy bodies. This demonstrates that despite pathological inattention and parietal damage, emotion and action-related information in fearful body language may be extracted automatically, biasing attentional selection and visual awareness. Our findings open new perspectives on the role of bodily expressions in attentional selection and suggest that a neural network in intact fronto-limbic and visual areas may still mediate reorienting of attention and preparation for action upon perceiving fear in others.


2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Bartosz Helfer ◽  
Stefanos Maltezos ◽  
Elizabeth Liddle ◽  
Jonna Kuntsi ◽  
Philip Asherson

Abstract Background. We investigated whether adults with attention-deficit/hyperactivity disorder (ADHD) show pseudoneglect—preferential allocation of attention to the left visual field (LVF) and a resulting slowing of mean reaction times (MRTs) in the right visual field (RVF), characteristic of neurotypical (NT) individuals —and whether lateralization of attention is modulated by presentation speed and incentives. Method. Fast Task, a four-choice reaction-time task where stimuli were presented in LVF or RVF, was used to investigate differences in MRT and reaction time variability (RTV) in adults with ADHD (n = 43) and NT adults (n = 46) between a slow/no-incentive and fast/incentive condition. In the lateralization analyses, pseudoneglect was assessed based on MRT, which was calculated separately for the LVF and RVF for each condition and each study participant. Results. Adults with ADHD had overall slower MRT and increased RTV relative to NT. MRT and RTV improved under the fast/incentive condition. Both groups showed RVF-slowing with no between-group or between-conditions differences in RVF-slowing. Conclusion. Adults with ADHD exhibited pseudoneglect, a NT pattern of lateralization of attention, which was not attenuated by presentation speed and incentives.


1992 ◽  
Vol 44 (3) ◽  
pp. 529-555 ◽  
Author(s):  
T. A Mondor ◽  
M.P. Bryden

In the typical visual laterality experiment, words and letters are more rapidly and accurately identified in the right visual field than in the left. However, while such studies usually control fixation, the deployment of visual attention is rarely restricted. The present studies investigated the influence of visual attention on the visual field asymmetries normally observed in single-letter identification and lexical decision tasks. Attention was controlled using a peripheral cue that provided advance knowledge of the location of the forthcoming stimulus. The time period between the onset of the cue and the onset of the stimulus (Stimulus Onset Asynchrony—SOA) was varied, such that the time available for attention to focus upon the location was controlled. At short SO As a right visual field advantage for identifying single letters and for making lexical decisions was apparent. However, at longer SOAs letters and words presented in the two visual fields were identified equally well. It is concluded that visual field advantages arise from an interaction of attentional and structural factors and that the attentional component in visual field asymmetries must be controlled in order to approximate more closely a true assessment of the relative functional capabilities of the right and left cerebral hemispheres.


Author(s):  
Richard Wennberg ◽  
Sukriti Nag ◽  
Mary-Pat McAndrews ◽  
Andres M. Lozano ◽  
Richard Farb ◽  
...  

A 24-year-old woman was referred because of incompletely-controlled complex partial seizures. Her seizures had started at age 21, after a mild head injury with brief loss of consciousness incurred in a biking accident, and were characterized by a sensation of bright flashing lights in the right visual field, followed by numbness and tingling in the right foot, spreading up the leg and to the arm, ultimately involving the entire right side, including the face. Occasionally they spread further to involve right facial twitching with jerking of the right arm and leg, loss of awareness and, at the onset of her epilepsy, rare secondarily generalized convulsions. Seizure frequency averaged three to four per month. She was initially treated with phenytoin and clobazam and subsequently changed to carbamazepine 800 milligrams per day. She also complained that her right side was no longer as strong as her left and that it was also numb, especially the leg, but felt that this weakness had stabilized or improved slightly over the past two years.


1976 ◽  
Vol 43 (1) ◽  
pp. 255-259 ◽  
Author(s):  
Takeshi Hatta

Study of matching judgment was designed to demonstrate an effect of lateral onset asynchrony in left-handed subjects, 7 males and 8 females. Japanese Hirakana letters or random forms were presented to one visual field first and to the other visual field second. 15 left-handers were requested to judge whether the successively presented stimuli were “same” or “different.” The results showed that for both types of stimuli there are no differences in accuracy of matching judgment whether the standard stimulus was presented to the right visual field first or to the left. These results indicate that the left-handed subjects may have a tendency toward hemispheric equi-potentiality for recognition of both verbal and non-verbal materials.


1987 ◽  
Vol 65 (3) ◽  
pp. 899-906 ◽  
Author(s):  
Edward J. Hass ◽  
Christopher W. Holden

It has been suggested that the hypnotic state results in a greater relative activation or priming of the right cerebral hemisphere than of the left hemisphere. The experiment reported here employed hypnosis to produce such a priming effect in a visual-detection task. Subjects were required to detect the presence or absence of a gap in outline squares presented either to the left visual field or right visual field, with response time as the primary dependent measure. Those subjects who were hypnotized produced a 50-msec. response time difference favoring squares presented to the left visual field whereas control subjects and simulator-control subjects showed no lateral asymmetries. The result is classified as a material-nonspecific priming effect and discussed with regard to the nature of processing resources.


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