Learning and memory processes in behavioural addiction: A systematic review.

Similar to addictive substances, addictive behaviours such as gambling and gaming are associated with maladaptive modulation of key brain areas and functional networks implicated in learning and memory. Therefore, this review sought to understand how different learning and memory processes relate to behavioural addictions and to unravel their underlying neural mechanisms. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we systematically searched four databases - PsycINFO, PubMed, Scopus, and Web of Science using the agreed-upon search string. Findings suggest altered executive function-dependent learning processes and enhanced habit learning in behavioural addiction. Whereas the relationship between working memory and behavioural addiction is influenced by addiction type, working memory aspect, and task nature. Additionally, long-term memory is incoherent in individuals with addictive behaviours. Consistently, neurophysiological evidence indicates alterations in brain areas and networks implicated in learning and memory processes in behavioural addictions. Overall, the present review argues that, like substance use disorders, alteration in learning and memory processes may underlie the development and maintenance of behavioural addictions.

The Level of Processing Modulates Visual Awareness: Evidence from Behavioral and Electrophysiological Measures.

The level of processing hypothesis (LoP) proposes that the transition from unaware to aware visual perception is graded for low-level (i.e., energy, features) stimulus whereas dichotomous for high-level (i.e., letters, words, meaning) stimulus. In this study, we explore the behavioral patterns and neural correlates associated with different depths (i.e., low vs. high) of stimulus processing. The low-level stimulus condition consisted of identifying the color (i.e., blue/blueish vs. red/reddish) of the target, and the high-level stimulus condition consisted of identifying stimulus category (animal vs. object). Behavioral results showed that the levels of processing manipulation produced significant differences in both the awareness rating distributions and accuracy performances between tasks, the low-level task producing more intermediate subjective ratings and linearly increasing accuracy performances and the high-level task producing less intermediate ratings and a more nonlinear pattern for accuracies. The electrophysiological recordings revealed two correlates of visual awareness, an enhanced posterior negativity in the N200 time window (visual awareness negativity [VAN]), and an enhanced positivity in the P3 time window (late positivity [LP]). The analyses showed a double dissociation between awareness and the level of processing hypothesis manipulation: Awareness modulated VAN amplitudes only in the low-level color task, whereas LP amplitude modulations were observed only in the higher level category task. These findings are compatible with a two-stage microgenesis model of conscious perception, where an early elementary phenomenal sensation of the stimulus (i.e., the subjective perception of color) would be indexed by VAN, whereas stimulus' higher level properties (i.e., the category of the target) would be reflected in the LP in a later latency range.

Competition between perceptual grouping cues in an indirect objective task.

The integration between Gestalt grouping cues has been a relatively unexplored issue in vision science. The present work introduces an objective indirect method based on the repetition discrimination task to determine the rules that govern the dominance dynamics of the competition between both intrinsic (Experiment 1: proximity vs luminance similarity) and extrinsic grouping cues (Experiment 2: common region vs connectedness) by means of objective measures of grouping (reaction times and accuracy). Prior to the main task, a novel objective equating task was introduced with the aim of equating the grouping strength of the cues for the visuomotor system. The main task included two single conditions with the grouping cues acting alone as well as two competing conditions displaying the grouping factors pitted against one another. Conventional aggregated analyses were combined with individual analysis and both revealed a consistent pattern of processing dominance of: (1) luminance similarity over proximity and (2) common region over connectedness. Interestingly, the individual analyses showed that, despite the heterogeneous responses to the single conditions, the pattern of dominance between cues was robustly homogeneous among the participants in the competing conditions.

Double-checking emotions: Valence and emotion category in contextual integration of facial expressions of emotion.

Faces showing happy, angry or fearful expressions were presented in emotionally congruent or incongruent situational contexts (short sentences describing events that would usually provoke happiness, anger or fear). The participants were assigned the task of judging whether the expression was appropriate or not to the context (congruency judgment task). Effects of emotional congruency were observed at both the behavioral and electrophysiological levels. Behavioral results showed evidence of congruency effects based on specific emotion content (e.g., less accurate and slower responses to fear faces in angry contexts). Event-related-potentials (ERP) results also showed emotional congruency effects at different post-stimulus onset latencies, beginning with the face-sensitive N170 component. An effect of emotional congruency was also shown on the N400 component that is typically sensitive to semantic congruency. Finally, a late positive potential (LPP), appearing at 450-650 ms post-stimulus onset showed a complex pattern of effects with modulations driven by the different combinations of contexts and target expressions. These results are interpreted in terms of a double process of valence and emotion checking that is supposed to underlie affective processing and contextual integration of facial expressions of emotions.

The nature of visual awareness at stimulus energy and feature levels: A backward masking study.

The level of processing (LoP) hypothesis proposes that low-level stimulus perception (i.e., stimulus energy and features) is a graded process whereas high-level (i.e., letters, words, meaning) stimulus perception is all-or-none. In the present study, we set up a visual masking design in order to examine the nature of visual awareness at stimulus energy (i.e., detection task) and feature levels (identification task) at specific individual target durations (13, 27, 40, 53, and 80 ms). We manipulated the strength of the masking to produce different visibility conditions and gathered participants' subjective (across a 4-point awareness scale) and objective (accuracy levels) awareness performances. We found that intermediate ratings (i.e., ratings 2 and 3, which index graded awareness experiences) were used in more than 50% of the trials for target presentations of 27, 40, 53, and 80 ms. In addition, objective accuracy performances for target presentations of 27 and 80 ms produced linearly increasing detection and identification accuracies across the awareness scale categories, respectively. Overall, our results suggest that visual awareness at energy and feature levels of stimulus perception may be graded. Furthermore, we found a divergence in detection and identification performance results, which emphasizes the need for an adequate election of target durations when studying different perceptual processes such as detection versus more complex stimulus identification processes. Finally, "clarity" in the perceptual awareness scale should be exhaustively defined depending on the level of processing of the stimulus, as participants may recalibrate the meaning of the different awareness categories depending on task demands.

Common region wins the competition between extrinsic grouping cues: Evidence from a task without explicit attention to grouping.

The competition between perceptual grouping factors is a relatively ignored topic, especially in the case of extrinsic grouping cues (e.g., common region or connectedness). Recent studies have examined the integration of extrinsic cues using tasks that induce selective attention to groups based on different grouping cues. However, this procedure could generate alternative strategies for task performance, which are non-related to the perceptual grouping operations. In the current work, we used an indirect task, i.e. repetition discrimination task, without explicit attention to grouping cues to further examine the rules that govern dominance between competing extrinsic grouping factors. This procedure allowed us to obtain an unbiased measure of the competition between common region and connectedness cues acting within the same display. The results corroborate previous data showing that grouping by common region dominated the perceived organization of the display, even though the phenomenological strength of the grouping cues was equated for each participant by means of a preliminary scaling task. Our results highlight the relevance of using indirect tasks as an essential tool for the systematic study of the integration of extrinsic grouping cues.

Dominance dynamics of competition between intrinsic and extrinsic grouping cues.

In the present study we examined the dominance dynamics of perceptual grouping cues. We used a paradigm in which participants selectively attended to perceptual groups based on several grouping cues in different blocks of trials. In each block, single and competing grouping cues were presented under different exposure durations (50, 150 or 350ms). Using this procedure, intrinsic vs. intrinsic cues (i.e. proximity and shape similarity) were compared in Experiment 1; extrinsic vs. extrinsic cues (i.e. common region and connectedness) in Experiment 2; and intrinsic vs. extrinsic cues (i.e. common region and shape similarity) in Experiment 3. The results showed that in Experiment 1, no dominance of any grouping cue was found: shape similarity and proximity grouping cues showed similar reaction times (RTs) and interference effects. In contrast, in Experiments 2 and 3, common region dominated processing: (i) RTs to common region were shorter than those to connectedness (Exp. 2) or shape similarity (Exp. 3); and (ii) when the grouping cues competed, common region interfered with connectedness (Exp. 2) and shape similarity (Exp. 3) more than vice versa. The results showed that the exposure duration of stimuli only affected the connectedness grouping cue. An important result of our experiments indicates that when two grouping cues compete, both the non-attended intrinsic cue in Experiment 1, and the non-dominant extrinsic cue in Experiments 2 and 3, are still perceived and they are not completely lost.

The Madrid Affective Database for Spanish (MADS): Ratings of Dominance, Familiarity, Subjective Age of Acquisition and Sensory Experience.

The current study presents ratings by 540 Spanish native speakers for dominance, familiarity, subjective age of acquisition (AoA), and sensory experience (SER) for the 875 Spanish words included in the Madrid Affective Database for Spanish (MADS). The norms can be downloaded as supplementary materials for this manuscript from https://figshare.com/s/8e7b445b729527262c88 These ratings may be of potential relevance to researches who are interested in characterizing the interplay between language and emotion. Additionally, with the aim of investigating how the affective features interact with the lexicosemantic properties of words, we performed correlational analyses between norms for familiarity, subjective AoA and SER, and scores for those affective variables which are currently included in the MADs. A distinct pattern of significant correlations with affective features was found for different lexicosemantic variables. These results show that familiarity, subjective AoA and SERs may have independent effects on the processing of emotional words. They also suggest that these psycholinguistic variables should be fully considered when formulating theoretical approaches to the processing of affective language.

Neural correlates of an early attentional capture by positive distractor words.

Exogenous or automatic attention to emotional distractors has been observed for emotional scenes and faces. In the language domain, however, automatic attention capture by emotional words has been scarcely investigated. In the current event-related potentials study we explored distractor effects elicited by positive, negative and neutral words in a concurrent but distinct target distractor paradigm. Specifically, participants performed a digit categorization task in which task-irrelevant words were flanked by numbers. The results of both temporo-spatial principal component and source location analyses revealed the existence of early distractor effects that were specifically triggered by positive words. At the scalp level, task-irrelevant positive compared to neutral and negative words elicited larger amplitudes in an anterior negative component that peaked around 120 ms. Also, at the voxel level, positive distractor words increased activity in orbitofrontal regions compared to negative words. These results suggest that positive distractor words quickly and automatically capture attentional resources diverting them from the task where attention was voluntarily directed.