A color-digit Stroop task shows numerical influence on numerosity processing.

The numerical Stroop task involves presenting participants with two digits that differ in physical size and numerical value and asking them to report which digit had the larger size or value while ignoring the other dimension. Previous studies show that participants have difficulty ignoring the irrelevant dimension and thus have implications on the automaticity of numerical processing. The present study investigates the automatic influence of numerical value on numerosity processing in a novel Stroop-like task. In two experiments, participants were presented with digits made of colored stripes and asked to identify the number of different colors. In both experiments, interference and facilitation effects were found, supporting the automaticity of symbolic number processing and its influence on numerosity processing. These findings expand upon previous research on numerical as well as counting Stroop tasks, and have potential implications for studying interference and basic numerical processing in children and clinical populations.

Evidence for Two Types of Task Conflict in a Color-Digit Stroop Task.

In the present study, we conducted a Stroop-like task in which the participants were required to decide whether the presented stimulus, which could be either a colored digit or a colored rectangle, consisted of more or less than five colors. Like other Stroop-like tasks, the stimuli could be congruent (the stimulus was a digit that was equal to the presented number of colors), incongruent (the stimulus was a digit that was different than the presented number of colors), or neutral (a colored rectangle). We utilized a two-to-one response setting so that in some incongruent trials the digit and the number of colors would elicit the same response (e.g., the digit 3 containing two colors; both are smaller than 5), while in some incongruent trials, the digit and the number of colors would elicit different responses (e.g., the digit 3 containing 6 colors). This enabled us to measure both conflicts arising from stimulus-stimulus and stimulus-response compatibilities. Our results indicated the existence of stimulus-stimulus compatibility (SSC), stimulus-response compatibility (SRC), and task conflict. Interestingly, these effects were in interaction with the number of colors, so that in small numbers, SSC and SRC were found, and in large numbers, SRC and task conflict were found. Moreover, the results suggest that our task includes two types of task conflict that are raised due to three different tasks: processing the meaning of the digit vs. estimating the number of colors and counting the number of colors vs. estimating the number of colors.

Evidence for Automatic, Stimulus Driven, Arithmetic Processing of Single-digit Multiplication Problems.

Certain stimuli can automatically trigger different behaviors in a stimulus-driven manner. To investigate whether mathematical equations automatically trigger the tendency to engage in arithmetic processing, we asked whether the presentation of multiplication equations in an irrelevant dimension can trigger the automatic task of arithmetic processing and if so, which processes are involved. To that end, we employed a color-naming task in which participants had to name the color of different stimuli, such as: mathematical equations (e.g., 4 × 6 = 24), neutral-symbols (e.g., ####), neutral-words (e.g., building), and same-number strings (e.g., 11111), which appeared as one of four different colors. We found that mathematical equations and regular words in the irrelevant dimension triggered more task conflict (i.e., color naming's reaction time was longer) as compared to same-number strings. In addition, we found evidence for the automatic activation of different numerical processes; such that large-size equations (7 × 9 = 63) triggered more conflict as compared with small-size (2 × 3 = 6) equations and same-parity incorrect equations (3 × 2 = 8) triggered more conflict as compared to different-parity incorrect equations (4 × 2 = 9). We found no evidence indicating a distinction between the correct and incorrect equations. We discussed the relevance of the findings to the automaticity of arithmetic abilities and other domains in numerical cognition.

Control your emotions: evidence for a shared mechanism of cognitive and emotional control.

The current investigation examined the bidirectional effects of cognitive control and emotional control and the overlap between these two systems in regulating emotions. Based on recent neural and cognitive findings, we hypothesised that two control systems largely overlap as control recruited for one system (either emotional or cognitive) can be used by the other system. In two experiments, participants completed novel versions of either the Stroop task (Experiment 1) or the Flanker task (Experiment 2) in which the emotional and cognitive control systems were actively manipulated into either a high or low emotional-load condition (achieved by varying the proportions of negative-valence emotional cues) and a high and a low cognitive control condition (achieved through varying the proportion of conflict-laden trials). In both experiments, participants' performance was impaired when both emotional and cognitive control were low, but significantly and similarly improved when one of the two control mechanisms were activated - the emotional or the cognitive. In Experiment 2, performance was further improved when both systems were activated. Our results give further support for a more integrative notion of control in which the two systems (emotional and cognitive control) not only influence each other, but rather extensively overlap.

The contribution of difficulty of an irrelevant task to task conflict.

In the standard colour-word Stroop task, participants are presented with colour words and required to respond to their colour while ignoring their meaning. Two types of conflict might occur in such experiments: information conflict and task conflict. Information conflict reflects the processing of two contradicting pieces of information and is indicated by shorter reaction times (RTs) in congruent than in incongruent trials. Task conflict reflects the additional effort associated with performing two tasks, as opposed to one, and is indicated by shorter RTs in neutral trials than in congruent trials (termed reverse facilitation). While information conflict is commonly seen in Stroop and Stroop-like tasks, task conflict is rarely observed. In the present study, participants were presented with coloured segments that, by applying Gestalt principles, could be perceived as colour words. We found that incongruent trials were slower than congruent trials, suggesting that participants successfully perceived the colour words, which led to involuntary reading. In addition, reversed facilitation was found so that neutral trials (i.e., trials that only consist of one task) were faster than congruent trials (as well as incongruent trials; both consist of two tasks). The presence of both interference from the incongruent trials and reverse facilitation suggests that involuntary reading could also occur in scenarios requiring cognitive effort.

Proactive control affects task conflict beyond contingency learning.

Various models of the Stroop task suggest that proactive task control adaptation accounts for the modulation of task conflict in different conditions of the Stroop task, for example, when task conflict is very frequent or very infrequent. Other researchers have argued that a contingency learning of colour-word associations is the main contributor to the modulations of the Stroop effect. In this work, we constructed a design that controls for confounds that are suspected to rule out the role of control adaptation in the Stroop task. We focused on one type of conflict-task conflict and tested whether colour-naming of neutral-words (where task conflict is present) differed from colour-naming of neutral-symbols (where task conflict is not present) in four different conditions: mostly words-congruent, mostly words-incongruent, mostly words-neutral, or mostly non-words-shape. Importantly, the conditions used for the task conflict marker were identical in all four conditions. We found that the marker of task conflict (reaction time [RT] for neutral-words > RT for neutral-symbols) was significant in the mostly non-words-shape condition, where proactive task control is relaxed, but not in the mostly words conditions, where proactive task control is activated, with no difference between these three words conditions. These findings suggest that control adaptation is the main contributor to the modulations of the Stroop effect. The relevance of the results to the current literature is discussed and the results are explained in light of the proactive control-task conflict (PC-TC) model.

Post-traumatic stress in war veterans and secondary traumatic stress among parents of war veterans five years after the 2014 Israel-Gaza military conflict.

Secondary traumatic stress (STS) has been studied in therapists, spouses, and mainly in children of traumatised individuals. To date, the relationship between children's posttraumatic stress disorder (PTSD) symptoms and their parents' mental health outcomes have been understudied, and specifically, long term STS symptoms of parents of war veterans were not investigated. The current study examined PTSD symptoms among veterans of the 2014 Israel-Gaza war and STS among their parents, five years after the war. The control group consisted of veterans from combat military units who were on active duty at the time of the war but did not actively participate in the war (stand-by units) - providing a natural experiment condition. We found that PTSD symptoms were almost twice as high in the directly active war veterans (DAV, N = 32) group compared to the indirectly active war veterans (IAV, N = 26) group. Results showed that mothers had higher STS symptoms in general, and DAV PTSD symptoms correlated with their fathers STS symptoms. The current study provides novel evidence for: (a) subclinical PTSD symptoms in war veterans 5 years after the war, and (b) transmission of trauma from war veterans to their parents. The overall negative effect of sending a child to war on the parents are also discussed.

The current study examined post-traumatic stress symptoms among undiagnosed war veterans of the 2014­2014 Israel-Gaza Military Conflict compared to matched control who were on active military duty at the same time but did not actively participate in the war. We found higher post-traumatic stress symptoms in the veterans who actively participated in the war, roughly five years after the war.Parents of veterans who actively participated in the war exhibited higher secondary traumatic stress compared to parents of veterans who did not actively participate in the war. This is especially interesting given that parents of all veterans were not aware of their whereabouts during the war. Overall, mothers exhibited higher secondary traumatic stress compared to fathers. However, fathers were more 'in-sync' with their sons' traumatic experience as evident by a significant correlation between the war veterans' post-traumatic stress and the fathers' secondary traumatic stress symptoms.

What is word? The boundary conditions of task conflict in the Stroop task.

The Stroop task is characterized by two types of conflicts-information conflict (between the incongruent word and ink color) and task conflict (between the relevant color-naming task and the competing, irrelevant, stimulus-driven, word reading task). It is not yet clear what stimuli trigger the task of reading, and thus task conflict, and to what extent. In the current study, we applied a novel low-control (high neutral proportion) between-subject design to test the effect of different neutral conditions (symbols, same-letter strings, illegal-letter strings, pseudo-words, and real-words) on task conflict, in both manual and vocal response-types. Results indicated that in the manual task, a reverse facilitation effect, a signature of task conflict, appeared in all non-word conditions in a similar magnitude, but did not appear in the real-words condition. In the vocal task, reverse facilitation was found only in the symbols condition, regular facilitation was exhibited in all other neutral conditions, and larger facilitation appeared in the real-words condition. Our results indicate that the reading process and the activation of task conflict, depend on response-types (manual vs. vocal). In both response-types we found support for a word superiority effect, such that words trigger task conflict to a greater extent, however, we only observed an orthographic effect in the vocal response-type where stimuli consisting of letters triggered the reading task. We concluded that in the manual response-type, conflict arises only in the lexical route, whilst in the vocal response-type, conflict arises in the lexical and orthographic routes.

The Influence of Response Inhibition Training on Food Consumption and Implicit Attitudes toward Food among Female Restrained Eaters.

Restrained eaters display difficulties engaging in self-control in the presence of food. Undergoing cognitive training to form associations between palatable food and response inhibition was found to improve self-control and influence eating behaviors. The present study assessed the impact of two such response inhibition trainings on food consumption, food-related anxiety, and implicit attitudes toward food among female restrained eaters (Dutch Eating Behavior Questionnaire-restrained eating subscale ≥ 2.5). In Experiment 1, 64 restrained eaters completed either one of two training procedures in which they were asked to classify food vs. non-food images: a food-response training, in which stop cues were always associated with non-food images, or a balanced food-response/inhibition training, in which participants inhibited motor actions to food and non-food stimuli equally. The results revealed reduced snack consumption following the food-response/inhibition training compared to the food-response training. The food-response training was associated with increased levels of food-related anxiety. In Experiment 2, the same training procedures were administered to 47 restrained eaters, and implicit attitudes toward palatable foods were assessed. The results revealed an increase in positive implicit attitudes toward palatable foods in the food-response/inhibition group but not in the food-response training group. The results suggest that balancing response inhibition and execution across food and non-food stimuli may reduce overeating while retaining positive attitudes toward food among female restrained eaters.

Task Conflict and Task Control: A Mini-Review.

Stimulus-driven behaviors are triggered by the specific stimuli with which they are associated. For example, words elicit automatic reading behavior. When stimulus-driven behaviors are incongruent with one's current goals, task conflict can emerge, requiring the activation of a task control mechanism. The Stroop task induces task conflict by asking participants to focus on color naming and ignore the automatic, stimulus-driven, irrelevant word reading task. Thus, task conflict manifests in Stroop incongruent as well as in congruent trials. Previous studies demonstrated that when task control fails, reaction times in congruent trials slow down, leading to a reversed facilitation effect. In the present mini-review, we review the literature on the manifestation of task conflict and the recruitment of task control in the Stroop task and present the physiological and behavioral signatures of task control and task conflict. We then suggest that the notion of task conflict is strongly related to the concept of stimulus-driven behaviors and present examples for the manifestation of stimulus-driven task conflict in the Stroop task and additional tasks, including object-interference and affordances tasks. The reviewed literature supports the illustration of task conflict as a specific type of conflict, which is different from other conflict types and may manifest in different tasks and under diverse modalities of response.

The Effect of Trier Social Stress Test (TSST) on Item and Associative Recognition of Words and Pictures in Healthy Participants.

Psychological stress, induced by the Trier Social Stress Test (TSST), has repeatedly been shown to alter memory performance. Although factors influencing memory performance such as stimulus nature (verbal/pictorial) and emotional valence have been extensively studied, results whether stress impairs or improves memory are still inconsistent. This study aimed at exploring the effect of TSST on item versus associative memory for neutral, verbal, and pictorial stimuli. 48 healthy subjects were recruited, 24 participants were randomly assigned to the TSST group and the remaining 24 participants were assigned to the control group. Stress reactivity was measured by psychological (subjective state anxiety ratings) and physiological (Galvanic skin response recording) measurements. Subjects performed an item-association memory task for both stimulus types (words, pictures) simultaneously, before, and after the stress/non-stress manipulation. The results showed that memory recognition for pictorial stimuli was higher than for verbal stimuli. Memory for both words and pictures was impaired following TSST; while the source for this impairment was specific to associative recognition in pictures, a more general deficit was observed for verbal material, as expressed in decreased recognition for both items and associations following TSST. Response latency analysis indicated that the TSST manipulation decreased response time but at the cost of memory accuracy. We conclude that stress does not uniformly affect memory; rather it interacts with the task's cognitive load and stimulus type. Applying the current study results to patients diagnosed with disorders associated with traumatic stress, our findings in healthy subjects under acute stress provide further support for our assertion that patients' impaired memory originates in poor recollection processing following depletion of attentional resources.

Negative Emotional Arousal Impairs Associative Memory Performance for Emotionally Neutral Content in Healthy Participants.

The effect of emotional arousal on memory presents a complex pattern with previous studies reporting conflicting results of both improved and reduced memory performance following arousal manipulations. In this study we further tested the effect of negative emotional arousal (NEA) on individual-item recognition and associative recognition of neutral stimuli in healthy participants, and hypothesized that NEA will particularly impair associative memory performance. The current study consists of two experiments; in both, participants studied a list of word-pairs and were then tested for items (items recognition test), and for associations (associative recognition test). In the first experiment, the arousal manipulation was induced by flashing emotionally-negative or neutral pictures between study-pairs while in the second experiment arousal was induced by presenting emotionally-negative or neutral pictures between lists. The results of the two experiments converged and supported an associative memory deficit observed under NEA conditions. We suggest that NEA is associated with an altered ability to bind one stimulus to another as a result of impaired recollection, resulting in poorer associative memory performance. The current study findings may contribute to the understanding of the mechanism underlying memory impairments reported in disorders associated with traumatic stress.

Transient Adverse Side Effects During Neurofeedback Training: A Randomized, Sham-Controlled, Double Blind Study.

The benefits of clinical neurofeedback training are well known, however, its adverse side-effects are less studied. This research focuses on the transient adverse side effects of neurofeedback training via a double-blind, sham/controlled methodology. Thirty healthy undergraduate students volunteers were randomly divided into three treatment groups: increasing a modified Sensory Motor Rhythm, increasing Upper Alpha, and Sham/control group who receive a random reward. The training sessions were administered for a total of ten sessions. Questionnaires of transient adverse side effects were completed by all volunteers before each session. The results suggest that similar to most medical treatments, neurofeedback can cause transient adverse side effects. Moreover, most participants reported experiencing some side effects. The side effects can be divided into non-specific side effect, associated with the neurofeedback training in general and specific ones associated with the particular protocol. Sensory Motor Rhythm protocol seems to be the most sensitive to side effects.

Influence of electroencephalography neurofeedback training on episodic memory: a randomized, sham-controlled, double-blind study.

The relationships between memory processes and oscillatory electroencephalography (EEG) are well established. Neurofeedback training (NFT) may cause participants to better regulate their brain EEG oscillations. The present study is a double-blind sham-controlled design investigating the effect of NFT on memory. NFT included up-training upper alpha (UA) band, up-training sensory-motor rhythm (SMR) band and sham protocol. Thirty healthy adult volunteers were randomly divided into three treatment groups. NFT sessions (30 min each) took place twice weekly for a total of 10 sessions while memory testing took place pre- and post-training. The results indicate dissociation between SMR and UA NFT and different memory processes. While the SMR protocol resulted in improving automatic, item-specific and familiarity-based processes in memory, the UA protocol resulted in improved strategic and controlled recollection. The implications of the results are discussed.