Domain-specific control of selective attention

Load effect of visual working memory on distractor interference: An investigation with two replication experiments

Konstantinou et al. (Experiment 1B; Attention, Perception, & Psychophysics, 76, 1985-1997, 2014) reported that an increase in visual short-term memory (VSTM) load reduced distractor interference in the flanker task. Yao et al. (Experiment 3; Attention, Perception, & Psychophysics, 82, 3291-3313, 2020) replicated the design of Konstantinou et al.'s experiment and showed that the VSTM load did not modulate the distractor interference effect, contradicting the original findings. However, it is unknown whether differences in task-design between the two experiments contributed to the inconsistent results. Therefore, we first replicated the original two studies with Experiment 1 (N = 54) and Experiment 2 (N = 54) and performed a statistical comparison between the data from these two experiments. In a third experiment (N = 28), we incorporated articulatory suppression into the design to exclude possible effects of verbalization. According to the ANOVA analyses, the VSTM load did not change the level of distractor interference in all three experiments, indicating that differences in task design alone do not explain the inconsistency.

Selective memory disrupted in intra-modal dual-task encoding conditions

Given natural memory limitations, people can generally attend to and remember high-value over low-value information even when cognitive resources are depleted in older age and under divided attention during encoding, representing an important form of cognitive control. In the current study, we examined whether tasks requiring overlapping processing resources may impair the ability to selectively encode information in dual-task conditions. Participants in the divided-attention conditions of Experiment 1 completed auditory tone-distractor tasks that required them to discriminate between tones of different pitches (audio-nonspatial) or auditory channels (audio-spatial), while studying items in different locations in a grid (visual-spatial) differing in reward value. Results indicated that, while reducing overall memory accuracy, neither cross-modal auditory distractor task influenced participants' ability to selectively encode high-value items relative to a full attention condition, suggesting maintained cognitive control. Participants in Experiment 2 studied the same important visual-spatial information while completing demanding color (visual-nonspatial) or pattern (visual-spatial) discrimination tasks during study. While the cross-modal visual-nonspatial task did not influence memory selectivity, the intra-modal visual-spatial secondary task eliminated participants' sensitivity to item value. These results add novel evidence of conditions of impaired cognitive control, suggesting that the effectiveness of top-down, selective encoding processes is attenuated when concurrent tasks rely on overlapping processing resources.

Practice Effects, Test-Retest Reliability, and Minimal Detectable Change of the Ruff 2 and 7 Selective Attention Test in Patients with Schizophrenia

BACKGROUND

The Ruff 2 and 7 Selective Attention Test (RSAT) is designed to measure selective attention. It tests automatic detection speed (ADS), automatic detection errors (ADE), automatic detection accuracy (ADA), controlled search speed (CSS), controlled search errors (CSE), and controlled search accuracy (CSA). The purpose of this study was to examine the test-retest reliability, practice effect, and minimum detectable change (MDC) of the RSAT in patients with schizophrenia.

METHODS

A total of 101 patients with schizophrenia completed the RSAT twice at a 4-week interval. The intra-class correlation coefficient (ICC), paired t test, and effect size were used to examine the test-retest reliability and practice effect. The standard error of measurement (SEM) and MDC were calculated.

RESULTS

The difference scores between the two assessments were significant in all the indexes. The absolute effect sizes were 0.14 to 0.30. The ICCs of the RSAT ranged from 0.69 to 0.91. The MDC% in the indexes of ADS, ADA, and CSA of the RSAT were <30%.

CONCLUSIONS

The RSAT is reliable for assessing selective attention in patients with schizophrenia. The RSAT has good to excellent test-retest reliability, a trivial to small practice effect, and indexes of ADS, ADA, and CSA, representing acceptable random measurement error.

Out with the Old and in with the New: the Contribution of Prefrontal and Cerebellar Areas to Backward Inhibition

The inhibitory mechanism named backward inhibition (BI) counteracts interference of previous tasks supporting task switching. For instance, if task set A is inhibited when switching to task B, then it should take longer to immediately return to task set A (as occurring in an ABA sequence), as compared to a task set that has not been just inhibited (as occurring in a CBA sequence), because extra time will be needed to overcome the inhibition of task set A.The evidenced prefrontal and cerebellar role in inhibitory control suggests their involvement even in BI. Here, for the first time, we modulated the excitability of multiple brain sites (right presupplementary motor area (pre-SMA), left and right cerebellar hemispheres) through continuous theta burst stimulation (cTBS) in a valuable sham-controlled order-balanced within-subject experimental design in healthy individuals performing two domain-selective (verbal and spatial) task-switching paradigms. Verbal BI was abolished by prefrontal or cerebellar stimulations through opposite alterations of the basal pattern: cTBS on pre-SMA increased CBA reaction times, disclosing the current prefrontal inhibition of any interfering old task. Conversely, cerebellar cTBS decreased ABA reaction times, disclosing the current cerebellar recognition of sequences in which it is necessary to overcome previously inhibited events.

Neural Correlates of Workload Transition in Multitasking: An ACT-R Model of Hysteresis Effect

This study investigated the effect of task demand transitions at multiple levels of analysis including behavioral performance, subjective rating, and brain effective connectivity, while comparing human data to Adaptive Control of Thought-Rational (ACT-R) simulated data. Three stages of task demand were designed and performed sequentially (Low-High-Low) during AF-MATB tasks, and the differences in neural connectivity during workload transition were identified. The NASA Task Load Index (NASA-TLX) and the Instantaneous Self-Assessment (ISA) were used to measure the subjective mental workload that accompanies the hysteresis effect in the task demand transitions. The results found significant hysteresis effects on performance and various brain network measures such as outflow of the prefrontal cortex and connectivity magnitude. These findings would assist in clarifying the direction and strength of the Granger Causality under demand transitions. As a result, these findings involving the neural mechanisms of hysteresis effects in multitasking environments may be utilized in applications of neuroergonomics research. The ability to compare data derived from human participants to data gathered by the ACT-R model allows researchers to better account for hysteresis effects in neuro-cognitive models in the future.

Neurophysiological Modulations of Non-Verbal and Verbal Dual-Tasks Interference during Word Planning

Running a concurrent task while speaking clearly interferes with speech planning, but whether verbal vs. non-verbal tasks interfere with the same processes is virtually unknown. We investigated the neural dynamics of dual-task interference on word production using event-related potentials (ERPs) with either tones or syllables as concurrent stimuli. Participants produced words from pictures in three conditions: without distractors, while passively listening to distractors and during a distractor detection task. Production latencies increased for tasks with higher attentional demand and were longer for syllables relative to tones. ERP analyses revealed common modulations by dual-task for verbal and non-verbal stimuli around 240 ms, likely corresponding to lexical selection. Modulations starting around 350 ms prior to vocal onset were only observed when verbal stimuli were involved. These later modulations, likely reflecting interference with phonological-phonetic encoding, were observed only when overlap between tasks was maximal and the same underlying neural circuits were engaged (cross-talk).

The effects of aging on the working memory processes of multimodal information

Normal aging is associated with deficits in working memory processes. However, the majority of research has focused on storage or inhibitory processes using unimodal paradigms, without addressing their relationships using different sensory modalities. Hence, we pursued two objectives. First, was to examine the effects of aging on storage and inhibitory processes. Second, was to evaluate aging effects on multisensory integration of visual and auditory stimuli. To this end, young and older participants performed a multimodal task for visual and auditory pairs of stimuli with increasing memory load at encoding and interference during retention. Our results showed an age-related increased vulnerability to interrupting and distracting interference reflecting inhibitory deficits related to the off-line reactivation and on-line suppression of relevant and irrelevant information, respectively. Storage capacity was impaired with increasing task demands in both age groups. Additionally, older adults showed a deficit in multisensory integration, with poorer performance for new visual compared to new auditory information.

Out with the Old and in with the New--Is Backward Inhibition a Domain-Specific Process?

Effective task switching is supported by the inhibition of the just executed task, so that potential interference from previously executed tasks is adaptively counteracted. This inhibitory mechanism, named Backward Inhibition (BI), has been inferred from the finding that switching back to a recently executed task (A-B-A task sequence) is harder than switching back to a less recently executed task (C-B-A task sequence). Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material. To address this issue, a group of individuals with Williams syndrome (WS) characterized by specific difficulties in maintaining and processing visuo-spatial, but not verbal, information, and a mental age- and gender-matched group of typically developing (TD) children were subjected to three task-switching experiments requiring verbal or visuo-spatial material to be processed. Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching. Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.

A computer-based selective visual attention test for first-grade school children: design, development and psychometric properties

BACKGROUND

Visual attention is known as a critical base for learning. The purpose of the present study was to design, develop and evaluate the test-retest and internal consistency reliability as well as face, content and convergent validity of the computer- based selective visual attention test (SeVAT) for healthy first-grade school children.

METHODS

In the first phase of this study, the computer-based SeVAT was developed in two versions of original and parallel. Ten experts in occupational therapy helped to measure the content validity using the CVR and CVI methods. Face validity was measured through opinions collected from 10 first-grade children. The convergent validity of the test was examined using the Spearman correlation between the SeVAT and Stroop test. In addition, test-retest reliability was determined by measuring the intra-class correlation (ICC) between the original and parallel versions of the SeVAT in a single session. The internal consistency was calculated by Cronbach's alpha coefficients. Sixty first grade children (30 girls/30boys) participated in this study.

RESULTS

The developed test was found to have good content and face validity. The SeVAT showed an excellent test-retest reliability (ICC= 0.778, p<0.001) and internal consistency (Cronbach's Alpha of original and parallel tests were 0.857 and 0.831, respectively). SeVAT and Stroop test demonstrated a positive correlation upon the convergent validity testing.

CONCLUSION

Our results suggested an acceptable reliability and validity for the computer-based SeVAT in the assessment of selective attention in children. Further research may warrant the differential validity of such a test in other age groups and neuro-cognitively disordered populations.