Effects of proactive interference on non-verbal working memory

The resolution of proactive interference in a novel visual working memory task: A behavioral and pupillometric study

Proactive interference (PI) occurs when previously learned information impairs memory for more recently learned information. Most PI studies have employed verbal stimuli, while the role of PI in visual working memory (VWM) has had relatively little attention. In the verbal domain, Johansson and colleagues (2018) found that pupil diameter - a real-time neurophysiological index of cognitive effort - reflects the accumulation and resolution of PI. Here we use a novel, naturalistic paradigm to test the behavioral and pupillary correlates of PI resolution for what-was-where item-location bindings in VWM. Importantly, in our paradigm, trials (PI vs. no-PI condition) are mixed in a block, and participants are naïve to the condition until they are tested. This design sidesteps concerns about differences in encoding strategies or generalized effort differences between conditions. Across three experiments (N = 122 total) we assessed PI's effect on VWM and whether PI resolution during memory retrieval is associated with greater cognitive effort (as indexed by the phasic, task-evoked pupil response). We found strong support for PI's detrimental effect on VWM (even with our spatially distributed stimuli), but no consistent link between interference resolution and effort during memory retrieval (this, even though the pupil was a reliable indicator that higher-performing individuals tried harder during memory encoding). We speculate that when explicit strategies are minimized, and PI resolution relies primarily on implicit processing, the effect may not be sufficient to trigger a robust pupillometric response.

Teleneuropsycological adaptation of the NEUROPSI Breve screening test

OBJECTIVE

Teleneuropsychology refers to the application of neuropsychology using video teleconferencing (VTC) techniques, whose methodology facilitates access to remote populations, a need that has increased due to the COVID-19 pandemic. Numerous investigations have documented the equivalence of different screening assessments (Mini Mental State Examination, Montreal Cognitive Assessment (MoCA) test and the Repeatable Battery for the Assessment for Neuropsychological Status) when applied via teleneuropsychology. The goal of the present work is to test the equivalence of the Brief Neuropsychological Battery in Spanish (NEUROPSI Breve), a neuropsychological screening instrument standardized for Spanish-speaking population that has reported a high sensitivity (91.6%) for identifying dementia, when applied in the VTC modality.

METHOD

In total, 32 Mexicans between 16 and 70 years were assessed, both in traditional (face-to-face) and VTC format with a 20 min wait between each application. Each participant was randomly assigned into one of four groups that were generated from the established conditions: the first application could be face-to-face or by VTC modality and an adapted or original version of NEUROPSI Breve would be applied; for the second application, the remaining modality and instrument would be used. Statistical analysis was carried out using the IBM Statistical Package for the Social Sciences (SPSS) software (v. 25).

RESULTS

The Wilcoxon signed-rank test presented statistically significant differences (Z = -2.79, P = .005). However, when applied to each one of the four evaluation groups, the Wilcoxon signed-rank test showed no statistically significant differences; the same results were found when starting with the original or adapted instrument, and when starting with the face-to-face modality (P < .005). However, differences are shown when starting with the online (VTC) modality (groups B and C) (P = .028).

CONCLUSIONS

The NEUROPSI Breve is applicable in both modalities, satisfying the needs of the population and the evaluation guidelines.

Tracking Proactive Interference in Visual Memory

The current contents of visual working memory can be disrupted by previously formed memories. This phenomenon is known as proactive interference, and it can be used to index the availability of old memories. However, there is uncertainty about the robustness and lifetime of proactive interference, which raises important questions about the role of temporal factors in forgetting. The present study assessed different factors that were expected to influence the persistence of proactive interference over an inter-trial interval in the visual recent probes task. In three experiments, participants encoded arrays of targets and then determined whether a single probe matched one of those targets. On some trials, the probe matched an item from the previous trial (a “recent negative”), whereas on other trials the probe matched a more distant item (a “non-recent negative”). Prior studies have found that recent negative probes can increase errors and slow response times in comparison to non-recent negative probes, and this offered a behavioral measure of proactive interference. In Experiment 1, factors of array size (the number of targets to be encoded) and inter-trial interval (300 ms vs. 8 s) were manipulated in the recent probes task. There was a reduction in proactive interference when a longer delay separated trials on one measure, but only when participants encoded two targets. When working memory capacity was strained by increasing the array size to four targets, proactive interference became stronger after the long delay. In Experiment 2, the inter-trial interval length was again manipulated, along with stimulus novelty (the number of stimuli used in the experiment). Proactive interference was modestly stronger when a smaller number of stimuli were used throughout the experiment, but proactive interference was minimally affected by the inter-trial interval. These findings are problematic for temporal models of forgetting, but Experiment 3 showed that proactive interference also resisted disruption produced by a secondary task presented within the inter-trial interval. Proactive interference was constantly present and generally resilient to the different manipulations. The combined data suggest a relatively durable, passive representation that can disrupt current working memory under a variety of different circumstances.

Proactive interference and the development of working memory

Working memory (WM), the ability to maintain information in service to a task, is characterized by its limited capacity. Several influential models attribute this limitation in a large extent to proactive interference (PI), the phenomenon that previously encoded, now-irrelevant information competes with relevant information. Here, we look back at the adult PI literature, spanning over 60 years, as well as recent results linking the ability to cope with PI to WM capacity. In early development, WM capacity is even more limited, yet an accounting for the role of PI has been lacking. Our Focus Article aims to address this through an integrative account: since PI resolution is mediated by networks involving the frontal cortex (particularly, the left inferior frontal gyrus) and the posterior parietal cortex, and since children have protracted development and less recruitment of these areas, the increase in the ability to cope with PI is a major factor underlying the increase in WM capacity in early development. Given this, we suggest that future research should focus on mechanistic studies of PI resolution in children. Finally, we note a crucial methodological implication: typical WM paradigms repeat stimuli from trial-to-trial, facilitating, inadvertently, PI and reducing performance; we may be fundamentally underestimating children's WM capacity. This article is categorized under: Psychology > Memory Neuroscience > Cognition Neuroscience > Development.

Effects of Exercise on Memory Interference in Neuropsychiatric Disorders

There are several mechanisms that cause memory impairment, including motivated forgetting, active forgetting, natural decay, and memory interference. Interference occurs when one is attempting to recall something specific, but there is conflicting information making it more difficult to recall the target stimuli. In laboratory settings, it is common to measure memory interference with paired associate tasks-usually utilizing the AB-CD, AB-AC, AB-ABr, or AB-DE AC-FG method. Memory impairments are frequent among those with neuropsychiatric disorders such as depression, schizophrenia, and multiple sclerosis. The memory effects of each condition differ, but are all related to alterations in brain physiology and general memory deterioration. Exercise, or physical activity, has been demonstrated to attenuate memory interference in some cases, but the mechanisms are still being determined. Further research is needed on memory interference, in regard to exercise and neuropsychiatric disorders.

The visual nonverbal memory trace is fragile when actively maintained, but endures passively for tens of seconds

Despite attempts at active maintenance in the focus of attention, the fragile nature of the visual nonverbal memory trace may be revealed when the retention interval between target memoranda and probed recall on a trial is extended. In contrast, a passively maintained or unattended visual memory trace may be revealed as persisting proactive interference extending across quite extended intervals between trials in a recent probes task. The present study, comprising five experiments, used this task to explore the persistence of such a passive visual memory trace over time. Participants viewed some target visual items (for example, abstract colored patterns) followed by a variable retention interval and a probe item. The task was to report whether the probe matched one of the targets or not. A decaying active memory trace was indicated by poorer performance as the memory retention interval was extended on a trial. However, when the probe was a member of the target set from the preceding trial, task performance was poorer than a comparison novel probe, demonstrating proactive interference. Manipulations of the intertrial interval revealed that the temporal persistence of the passive memory trace of an old target was impressive, and proactive interference was largely resilient to a simple ‘cued forgetting’ manipulation. These data support the proposed two-process memory conception (active–passive memory) contrasting fragile active memory traces decaying over a few seconds with robust passive traces extending to tens of seconds.

Behavioral measures of attention and cognitive control during a new auditory working memory paradigm

Proactive control is the ability to manipulate and maintain goal-relevant information within working memory (WM), allowing individuals to selectively attend to important information while inhibiting irrelevant distractions. Deficits in proactive control may cause multiple cognitive impairments seen in schizophrenia. However, studies of cognitive control have largely relied on visual tasks, even though the functional deficits in schizophrenia are more frequent and severe in the auditory domain (i.e., hallucinations). Hence, we developed an auditory analogue of a visual ignore/suppress paradigm. Healthy adults (N = 40) listened to a series of four letters (600-ms stimulus onset asynchrony) presented alternately to each ear, followed by a 3.2-s maintenance interval and a probe. Participants were directed either to selectively ignore (I) the to-be-presented letters at one ear, to suppress (S) letters already presented to one ear, or to remember (R) all presented letters. The critical cue was provided either before (I) or after (S) the encoding series, or simultaneously with the probe (R). The probes were encoding items presented to either the attended/not suppressed ear ("valid") or the ignored/suppressed ear ("lure"), or were not presented ("control"). Replicating prior findings during visual ignore/suppress tasks, response sensitivity and latency revealed poorer performance for lure than for control trials, particularly during the suppress condition. Shorter suppress than remember latencies suggested a behavioral advantage when discarding encoded items from WM. The paradigm-related internal consistencies and 1-week test-retest reliabilities (n = 38) were good to excellent. Our findings validate these auditory WM tasks as a reliable manipulation of proactive control and set the stage for studies with schizophrenia patients who experience auditory hallucinations.

Inhibitory Processes Training for School-age Children: Transfer Effects

Inhibition refers to a basic executive component that can be conceptualized as consisted of different inhibitory processes (i.e., perceptual, cognitive and response inhibition). These processes emerge during the first years of life, and since then are involved in different relevant every day activities. Different individual and contextual factors can modulate their developmental trajectories. The possibility of train in separate ways each inhibitory process is a subject of analysis. In such a context, the aims of this work were: (a) to design, implement and evaluate training of perceptual, cognitive and response inhibition processes, in a sample of school-aged children (6 to 8 years old); and (b) to analyze near, far, short- and long-transfer effects. An experimental design with three training groups (one for each inhibitory process) and an active control group was implemented. Near transfer effects were not observed. We found effects on a visuospatial working memory task in the short term, after the training in the response and cognitive inhibition, and effects on a fluid intelligence task in both the short and long term after the training in cognitive inhibition. The results contribute to a conceptualization of multidimensional inhibitory processes and the plausibility of training them during childhood.