Training the attentional blink: subclinical depression decreases learning potential.

The attentional blink (AB) reflects a temporal restriction of selective attention and is generally regarded as a very robust phenomenon. However, previous studies have found large individual differences in AB performance, and under some training conditions the AB can be reduced significantly. One factor that may account for individual differences in AB magnitude is the ability to accurately time attention. In the current study, we focus on the sensitivity for temporal information on the ability to control attention. Following a visual AB task, a time estimation task was presented in either the visual or auditory modality, followed by another visual AB task. It was found that the time estimation training in both the auditory and visual modality reduced AB magnitude. Although a reduction in AB magnitude was also observed when individuals were trained on a control task (either an auditory frequency or visual line length estimation task), the effect was significantly larger following the time estimation tasks. In addition, it was found that individuals who showed most improvement on the visual time estimation task, also showed the largest reduction in AB magnitude, which was not the case for individuals who were trained on the control tasks. Finally, a negative correlation was observed between depression scores (tested by Beck Depression Inventory-Short Form (BDI-SF) scores and the improvement in the AB and time estimation tasks. Our findings demonstrate clear links between timing ability and mechanisms to control attention and emotion.

Training-induced Changes in the Dynamics of Attention as Reflected in Pupil Dilation.

One of the major topics in attention literature is the attentional blink (AB), which demonstrates a limited ability to identify the second of two targets (T1 and T2) when presented in close temporal succession (200-500 msec). Given that the effect has been thought of as robust and resistant to training for over two decades, one of the most remarkable findings in recent years is that the AB can be eliminated after a 1-hr training with a color-salient T2. However, the underlying mechanism of the training effect as well as the AB itself is as of yet still poorly understood. To elucidate this training effect, we employed a refined version of our recently developed pupil dilation deconvolution method to track any training-induced changes in the amount and onset of attentional processing in response to target stimuli. Behaviorally, we replicated the original training effect with a color-salient T2. However, we showed that training without a salient target, but with a consistent short target interval, is already sufficient to attenuate the AB. Pupil deconvolution did not reveal any posttraining changes in T2-related dilation but instead an earlier onset of dilation around T1. Moreover, normalized pupil dilation was enhanced posttraining compared with pretraining. We conclude that the AB can be eliminated by training without a salient cue. Furthermore, our data point to the existence of temporal expectations at the time points of the trained targets posttraining. Therefore, we tentatively conclude that temporal expectations arise as a result of training.

Pupil dilation deconvolution reveals the dynamics of attention at high temporal resolution.

The size of the human pupil increases as a function of mental effort. However, this response is slow, and therefore its use is thought to be limited to measurements of slow tasks or tasks in which meaningful events are temporally well separated. Here we show that high-temporal-resolution tracking of attention and cognitive processes can be obtained from the slow pupillary response. Using automated dilation deconvolution, we isolated and tracked the dynamics of attention in a fast-paced temporal attention task, allowing us to uncover the amount of mental activity that is critical for conscious perception of relevant stimuli. We thus found evidence for specific temporal expectancy effects in attention that have eluded detection using neuroimaging methods such as EEG. Combining this approach with other neuroimaging techniques can open many research opportunities to study the temporal dynamics of the mind's inner eye in great detail.

The nature of hemispheric specialization for prosody perception.

Recent evidence suggests a relative right-hemispheric specialization for emotional prosody perception, whereas linguistic prosody perception is under bilateral control. It is still unknown, however, how the hemispheric specialization for prosody perception might arise. Two main hypotheses have been put forward. Cue-dependent hypotheses, on the one hand, propose that hemispheric specialization is driven by specialization for the non-prosody-specific processing of acoustic cues. The functional lateralization hypothesis, on the other hand, proposes that hemispheric specialization is dependent on the communicative function of prosody, with emotional and linguistic prosody processing being lateralized to the right and left hemispheres, respectively. In the present study, the functional lateralization hypothesis of prosody perception was systematically tested by instructing one group of participants to evaluate the emotional prosody, and another group the linguistic prosody dimension of bidimensional prosodic stimuli in a dichotic-listening paradigm, while event-related potentials were recorded. The results showed that the right-ear advantage was associated with decreased latencies for an early negativity in the contralateral hemisphere. No evidence was found for functional lateralization. These findings suggest that functional lateralization effects for prosody perception are small and support the structural model of dichotic listening.

The nature of affective priming in music and speech.

The phenomenon of affective priming has caught scientific interest for over 30 years, yet the nature of the affective priming effect remains elusive. This study investigated the underlying mechanism of cross-modal affective priming and the influence of affective incongruence in music and speech on negativities in the N400 time-window. In Experiment 1, participants judged the valence of affective targets (affective categorization). We found that music and speech targets were evaluated faster when preceded by affectively congruent visual word primes, and vice versa. This affective priming effect was accompanied by a significantly larger N400-like effect following incongruent targets. In this experiment, both spreading of activation and response competition could underlie the affective priming effect. In Experiment 2, participants categorized the same affective targets based on nonaffective characteristics. However, as prime valence was irrelevant to the response dimension, affective priming effects could no longer be attributable to response competition. In Experiment 2, affective priming effects were observed neither at the behavioral nor electrophysiological level. The results of this study indicate that both affective music and speech prosody can prime the processing of visual words with emotional connotations, and vice versa. Affective incongruence seems to be associated with N400-like effects during evaluative categorization. The present data further suggest a role of response competition during the affective categorization of music, prosody, and words with emotional connotations.

Testing the skill-based approach: Consolidation strategy impacts attentional blink performance.

Humans can learn simple new tasks very quickly. This ability suggests that people can reuse previously learned procedural knowledge when it applies to a new context. We have proposed a modeling approach based on this idea and used it to create a model of the attentional blink (AB). The main idea of the skill-based approach is that models are not created from scratch but, instead, built up from reusable pieces of procedural knowledge (skills). This approach not only provides an explanation for the fast learning of simple tasks but also shows much promise to improve certain aspects of cognitive modeling (e.g., robustness and generalizability). We performed two experiments, in order to collect empirical support for the model's prediction that the AB will disappear when the two targets are consolidated as a single chunk. Firstly, we performed an unsuccessful replication of a study reporting that the AB disappears when participants are instructed to remember the targets as a syllable. However, a subsequent experiment using easily combinable stimuli supported the model's prediction and showed a strongly reduced AB in a large group of participants. This result suggests that it is possible to avoid the AB with the right consolidation strategy. The skill-based approach allowed relating this finding to a general cognitive process, thereby demonstrating that incorporating this approach can be very helpful to generalize the findings of cognitive models, which otherwise tends to be rather difficult.

Two faces of perceptual awareness during the attentional blink: Gradual and discrete.

In a series of experiments, the nature of perceptual awareness during the attentional blink was investigated. Previous work has considered the attentional blink as a discrete, all-or-none phenomenon, indicative of general access to conscious awareness. Using continuous report measures in combination with mixture modeling, the outcomes showed that perceptual awareness during the attentional blink can be a gradual phenomenon. Awareness was not exclusively discrete, but also exhibited a gradual characteristic whenever the spatial extent of attention induced by the first target spanned more than a single location. Under these circumstances, mental representations of blinked targets were impoverished, but did approach the actual identities of the targets. Conversely, when the focus of attention covered only a single location, there was no evidence for any partial knowledge of blinked targets. These two different faces of awareness during the attentional blink challenge current theories of both awareness and temporal attention, which cannot explain the existence of gradual awareness of targets during the attentional blink. To account for the current outcomes, an adaptive gating model is proposed that casts awareness on a continuum between gradual and discrete, rather than as being of either single kind. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Widespread white matter aberration is associated with the severity of apathy in amnestic Mild Cognitive Impairment: Tract-based spatial statistics analysis.

Apathy is recognized as a prevalent behavioral symptom of amnestic Mild Cognitive Impairment (aMCI). In aMCI, apathy is associated with an increased risk and increases the risk of progression to Alzheimer's Disease (AD). Previous DTI study in aMCI showed that apathy has been associated with white matter alterations in the cingulum, middle and inferior longitudinal fasciculus, fornix, and uncinate fasciculus. However, the underlying white matter correlates associated with apathy in aMCI are still unclear. We investigated this relationship using whole-brain diffusion tensor imaging (DTI). Twenty-nine aMCI patients and 20 matched cognitively healthy controls were included. Apathy severity was assessed using the Apathy Evaluation Scale Clinician version. We applied the tract-based spatial statistics analyses to DTI parameters: fractional anisotropy (FA), mean diffusivity, axial diffusivity, and radial diffusivity to investigate changes in white matter pathways associated with the severity of apathy. No significant difference was found in any of the DTI parameters between aMCI and the control group. In aMCI, higher severity of apathy was associated with lower FA in various white matter pathways including the left anterior part of inferior fronto-occipital fasciculus/uncinate fasciculus, genu and body of the corpus callosum, superior and anterior corona radiata, anterior thalamic radiation of both hemispheres and in the right superior longitudinal fasciculus/anterior segment of arcuate fasciculus (p < .05, TFCE-corrected) after controlling for age, gender and GDS non-apathy. A trend association was observed in the right posterior corona radiata and corticospinal tract/internal capsule, and bilateral forceps minor (p < .065, TFCE-corrected). In conclusion, in aMCI, severity of apathy is associated with aberrant white matter integrity in widely distributed pathways, within and between hemispheres.

Differential effects of exogenous and endogenous cueing in multi-stream RSVP: implications for theories of attentional blink.

The attentional blink (AB) refers to the finding that performance on the second of two targets (T1 and T2) in a rapid serial visual presentation (RSVP) stream is impaired when the targets are presented within 200-500 ms. To explore the possible interaction between spatial attentional orienting and temporary attentional deficits, this study used central (endogenous) and peripheral (exogenous) cues in a multi-stream RSVP task and compared the endogenous and exogenous cueing effects inside and outside of the AB period. While the endogenous cueing effect was constant in magnitude over time, the exogenous cueing effect was significantly larger inside than outside of the AB period. Theoretical implications of these findings for the interaction between attention mechanisms in spatial and temporal domains are discussed.

A Skill-Based Approach to Modeling the Attentional Blink.

People can often learn new tasks quickly. This is hard to explain with cognitive models because they either need extensive task-specific knowledge or a long training session. In this article, we try to solve this by proposing that task knowledge can be decomposed into skills. A skill is a task-independent set of knowledge that can be reused for different tasks. As a demonstration, we created an attentional blink model from the general skills that we extracted from models of visual attention and working memory. The results suggest that this is a feasible modeling method, which could lead to more generalizable models.

Functional network topology associated with apathy in Alzheimer's disease.

BACKGROUND: Apathy, a common neuropsychiatric (NPS) in patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD), is associated with structural and metabolic brain changes. However, functional connectivity changes across the brain in association with apathy remain unclear. In this study, graph theoretical measures of integration and segregation from resting state functional connectivity in MCI and AD patients with low depression scores, and healthy controls. METHODS: In MCI and AD patients with low depression scores, graph theoretical measures of integration and segregation were derived from resting state functional connectivity in patients, which were compared between those with apathy (NPS_A, n = 21) to those without NPS (NPS_None, n = 28) and those with NPS other than apathy (NPS_NA, n = 38). Additionally, the same measures were compared between AD patients and healthy controls (amyloid uptake below threshold levels). RESULTS: Altered whole brain global efficiency and reduced local efficiency were found in NPS_A compared to NPS_None and NPS_NA. In similar contrasts, apathy was associated with increased participation coefficient in the frontoparietal and cingulo-opercular template-based networks. A study-specific network definition also showed similar results. In comparison, AD patients showed higher modularity compared to controls at the whole brain level and higher participation coefficient in the ventral attention network. LIMITATIONS: The severity and dimensions of apathy were not assessed. CONCLUSIONS: Loss of segregation in the frontoparietal and cingulo-opercular network, which are involved in the control of goal-directed behavior, was associated with apathy in MCI/AD. The results also suggest that network-level changes in AD patients may underlie specific NPS.

Too much control can hurt: a threaded cognition model of the attentional blink.

Explanations for the attentional blink (AB; a deficit in identifying the second of two targets when presented 200-500 ms after the first) have recently shifted from limitations in memory consolidation to disruptions in cognitive control. With a new model based on the threaded cognition theory of multi-tasking we propose a different explanation: the AB is produced by an overexertion of control. This overexertion is produced by a production rule that blocks target detection during memory consolidation. In addition to fitting many known effects in the literature, the model predicts that adding certain secondary tasks will decrease the AB. In Experiment 1, a secondary task is added to the AB task in which participants have to respond to a moving dot. As predicted, AB decreases. Experiment 2 expands this result by controlling for learning, and adds a second variation, rotating the first target. For this variation the model predicts an increase in AB, which is indeed what we found.

Working memory capacity, intelligence, and the magnitude of the attentional blink revisited.

The attentional blink (AB) is a well-established phenomenon in the study of attention. This deficit in reporting the second of two targets presented in rapid serial visual presentation when it occurs 200-500 ms after the first is considered to reflect a fundamental limitation in attentional processing. However, we recently reported that some individuals do not show an AB, and presented psychophysiological evidence that target processing differs between blinkers and non-blinkers. One possibility is that non-blinkers may have a larger WM capacity, allowing better attentional control. Here we explore the relation between the magnitude of the AB, general intelligence, and different measures of working memory (WM) and short-term memory (STM) capacity. Surprisingly, no correlation was found between memory capacity measures and AB magnitude, raising doubts about the generalizability of earlier findings of such a relationship.

Individual differences in the attentional blink. The important role of irrelevant information.

A well-established phenomenon in the study of attention is the attentional blink (AB): a deficit in reporting the second of two targets when it occurs 200-500 ms after the first. Although the effect has been shown to be robust in a wide variety of task conditions, we recently reported that some individuals show little or no AB, and presented psychophysiological evidence that target processing differs in nonblinkers (who do not show an AB) and blinkers (who do show an AB). Here we present evidence that the level of distractor processing and subsequent interference with target identification processes also differs between the two groups. In one task, two masked targets were centrally presented at varying temporal intervals, with or without additional distractors. In a second task, the masked targets were presented eccentrically, with or without the presence of a central sequential stream of the task-irrelevant distractors. In both cases, the presence of distractors led to an increased AB magnitude in blinkers, whereas performance for nonblinkers remained relatively unaffected. The results thus support the hypothesis that nonblinkers are more efficient in ignoring irrelevant information than blinkers.

A quick visual mind can be a slow auditory mind. Individual differences in attentional selection across modalities.

The human mind is severely limited in processing concurrent information at a conscious level of awareness. These temporal restrictions are clearly reflected in the attentional blink (AB), a deficit in reporting the second of two targets when it occurs 200-500 ms after the first. However, we recently reported that some individuals do not show a visual AB, and presented psychophysiological evidence that target processing differs between "blinkers" and "nonblinkers". Here, we present evidence that visual nonblinkers do show an auditory AB, which suggests that a major source of attentional restriction as reflected in the AB is likely to be modality-specific. In Experiment 3, we show that when the difficulty in identifying visual targets is increased, nonblinkers continue to show little or no visual AB, suggesting that the presence of an AB in the auditory but not in the visual modality is not due to a difference in task difficulty.

Beta-gamma oscillation reveals learning from unexpected reward in learners versus non-learners.

Beta-gamma oscillation has been demonstrated to be sensitive to unexpected reward feedback. However, it remains unclear whether beta-gamma activity manifests individual differences in reinforcement learning processing. Given that individuals differ largely in reinforcement learning tasks, we adapted the Friedland task and split subjects into two groups: learners who learned to choose the optimal card after training and non-learners who did not learn well. We used recorded electroencephalography signals to test the difference in brain activity between the learners and non-learners groups when participants conducted a time estimation task and received win and loss feedback in expected and unexpected conditions. The results revealed that the unexpected condition elicited a larger reward positivity amplitude than did the expected condition, but only in the learners group. No significant difference was found between the two groups for the expectancy effect on frontal-midline theta. The current results thus demonstrate that for learners, unexpected win feedback elicits a larger beta-gamma oscillation than expected win feedback, while this was not the case for non-learners. These results indicate that beta-gamma oscillation may reflect effective learning from positive reward prediction error, a finding that adds to the existing theories on learning processes.

Lower Choline and Myo-Inositol in Temporo-Parietal Cortex Is Associated With Apathy in Amnestic MCI.

Apathy is a common symptom in patients with amnestic mild cognitive impairment (aMCI) and is associated with an increased risk of progression to Alzheimer's disease (AD). The neural substrates underlying apathy in aMCI may involve multiple brain regions, including the anterior cingulate cortex and the temporo-parietal region. Here we investigated neurometabolites in brain regions that may underlie apathy in aMCI patients using proton magnetic resonance spectroscopy (1H-MRS). Twenty-eight aMCI patients with varying degrees of apathy and 20 matched controls underwent 1H-MRS. Spectra were acquired from single voxels in the posterior cingulate cortex (PCC), dorsal anterior cingulate cortex (DACC), right dorsolateral prefrontal cortex (DLPFC), and right temporo-parietal cortex (TPC). Apathy was measured with the Apathy Evaluation Scale (AES). Spearman partial correlations between metabolite concentrations in each region and severity of apathy were determined. Additionally, analyses of covariance (ANCOVA) were performed to determine whether metabolite changes differed between patients with or without clinically-diagnosed apathy. The degree of apathy was found to be negatively correlated with choline and myo-inositol (mI) in the TPC. Additional exploratory analyses suggested that N-acetylaspartate (NAA)/mI ratio was reduced in aMCI without clinical apathy but not in aMCI with clinical apathy. In the DACC, glutamate and glutamine (Glx) levels tended to be higher in the aMCI with apathy group compared to controls and reduced in association with depression scores. In conclusion, apathy in aMCI patients was associated with neurometabolite changes indicative of altered membranal integrity and glial function in the right TPC. Findings also indicated that in a clinically-diagnosed aMCI cohort, apathy symptoms may be suggestive of neural changes that are distinct from aMCI without apathy.

Rethinking neural efficiency: effects of controlling for strategy use.

A sentence verification task (SVT) was used to test whether differences in neural activation patterns that have been attributed to IQ may actually depend on differential strategy use between IQ groups. Electroencephalograms were recorded from 14 low (89 < IQ < 110) and 14 high (121 < IQ < 142) IQ individuals as they performed the SVT with either a spatial or verbal strategy. Event-related desynchronization in upper alpha (9.5-12.5 Hz) and theta (4-6 Hz) bands showed that different strategies evoked different activation patterns, but these patterns did not differ between groups. However, an IQ-related correlate was found in the preparation interval. Thus, although processing patterns during task performance seem to depend on the strategy used for task execution, preparation for task processing may depend on IQ.

Detection of emotional expressions in rapidly changing facial displays in high- and low-socially anxious women.

Facial information and attention to facial displays are distributed over spatial as well as temporal domains. Thus far, research on selective attention to (dis)approving faces in the context of social anxiety has concentrated primarily on the spatial domain. Using a rapid serial visual presentation (RSVP) paradigm, the present study examined the temporal characteristics of visual attention for happy and angry faces in high- (n=16) and low-socially anxious individuals (n=17), to test whether also in the temporal domain socially anxious individuals are characterized by threat-confirming attentional biases. Results indicated that presenting angry faces as the first target (T1) did not aggravate the detection of the emotional expression of the second target (T2). Yet, participants generally showed superior detection of the emotional expression of T2, if T2 was an angry face. Casting doubt on the role of such attenuated attentional blink for angry faces in social anxiety, no evidence emerged to indicate that this effect was relatively strong in high-socially anxious individuals. Finally, the presentation of an angry face as T2 resulted in a relatively hampered identification of a happy-T1. Again, this "backward blink" was not especially pronounced in high-socially anxious individuals. The present anger superiority effects are consistent with evolutionary models stressing the importance of being especially vigilant for signals of dominance. Since the effects were not especially pronounced in high-anxious individuals, the present study adds to previous findings indicating that socially anxious individuals are not characterized by a bias in the (explicit) detection of emotional expressions [Philippot, P., & Douilliez, C. (2005). Social phobics do not misinterpret facial expression of emotion. Behaviour Research and Therapy, 43, 639-652].

Cross-task repetition amnesia: Impaired recall of RSVP targets held in memory for a secondary task.

People often fail to select and encode the second of two targets presented within less than 500ms in rapid serial visual presentation (RSVP), an effect known as the attentional blink. We investigated how report of the two targets is affected when one of them is maintained in working memory for a secondary, memory-search task. The results showed that report of either target was impaired when it was a member of the memory set relative to when it was not. This effect was independent of both the temporal interval separating the RSVP target from the presentation of the memory set and the interval separating the targets. We propose that the deficit in recall occurs because the association between a target and the memory-search task interferes with the formation of a new association between that target and the following RSVP task, with the result that observers may be biased to ascribe the target only to the memory set.