Global shape integration and illusory form perception in the absence of awareness

Previous research on perceptual organization operations still provides contradictory evidence on whether the integration of sparse local elements into coherently unified shapes and the construction of the illusory form are accomplished without the need of awareness. In the present study, three experiments were conducted in which participants were presented with masked (Experiment 1, SOA = 27 ms; Experiment 2; SOA = 53 ms) and unmasked (Experiment 3) primes consisting of geometric shapes (a square or a diamond) that could be congruent or incongruent with subsequent probe stimuli (square vs. diamond). Furthermore, the primes were divided into: a grouping condition (where local elements may group together into global shapes), an illusory condition (where the arrangement of local elements produced illusory shapes) and a hybrid condition (where both operations were presented simultaneously). While no priming effects were found for the shortest SOA (27 ms), both grouping and illusory primes produced significant priming effects in the longer SOA (53 ms). On the other hand, results in Experiment 3 (unmasked) showed strong priming effects for the grouping of the inducers in both the grouping and the hybrid conditions, and also a significant but weaker priming effect for the illusory condition. Overall, our results support the possibility of the integration of local visual features into a global shape in the absence of awareness and, likewise, they suggest an early –subliminal– construction of the illusory shape, implying that feedback projections from higher to lower visual areas are not crucial in the construction of the illusory form.     

Behavioral memory induced by stimulation of the nucleus basalis: Effects of contingency reversal

Specific behavioral associative memory induced by stimulation of the cortically-projecting cholinergic nucleus basalis (NB) is dependent on intrinsic acetylcholine and shares with natural memory such features as associativity, specificity, rapid formation, consolidation and long-term retention. Herein, we examined extinction and the effects of stimulus pre-exposure. Two groups of adult male rats (n = 4 each) were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), constituting a pre-training behavioral frequency generalization gradient (BFGG). They next received a first session of training, 200 trials of a tone (8.00 kHz, 70 dB, 2 s) either paired with electrical stimulation of the NB (100 Hz, 0.2 s, ～67 μA, NBstm) (group IP) or unpaired (group IU). Twenty-four hours later, they were tested for behavioral memory by obtaining post-training BFGGs. Then the contingencies were reversed yet another 24 h later; the IP group received tone and NBstm unpaired and the IU group received them paired. A final set of generalization gradients was obtained the next day. All stimuli were presented with subjects under state control indexed by regular respiration. Tested 24 h post-initial training, the IP group developed specific associative behavioral memory indicated by increased responses only to CS-band frequencies, while the IU group did not. After subsequent training with unpaired stimuli, the IP group exhibited experimental extinction. Furthermore, after initial exposure to the CS and NBstm unpaired, the IU group exhibited a tendency toward reduced conditioning to CS/NBstm pairing and a significant increase in latency of conditioned responses. The present findings provide additional support for the hypothesis that engagement of the NB is sufficient to induce natural associative memory and suggest that activation of the NB may be a normal component in the formation of natural associative memory.     

Sensory memory consolidation observed: Increased specificity of detail over days

Memories are usually multidimensional, including contents such as sensory details, motivational state and emotional overtones. Memory contents generally change over time, most often reported as a loss in the specificity of detail. To study the temporal changes in the sensory contents of associative memory without motivational and emotional contents, we induced memory for acoustic frequency by pairing a tone with stimulation of the cholinergic nucleus basalis. Adult male rats were first tested for behavioral responses (disruption of ongoing respiration) to tones (1–15 kHz), yielding pre-training behavioral frequency generalization gradients (BFGG). They next received three days of training consisting of a conditioned stimulus (CS) tone (8.00 kHz, 70 dB, 2 s) either Paired (n = 5) or Unpaired (n = 5) with weak electrical stimulation (～48 μA) of the nucleus basalis (100 Hz, 0.2 s, co-terminating with CS offset). Testing for behavioral memory was performed by obtaining post-training BFGGs at two intervals, 24 and 96 h after training. At 24 h post-training, the Paired group exhibited associative behavioral memory manifested by significantly larger responses to tone than the Unpaired group. However, they exhibited no specificity in memory for the frequency of the tonal CS, as indexed by a flat BFGG. In contrast, after 96 h post-training the Paired group did exhibit specificity of memory as revealed by tuned BFGGs with a peak at the CS-band of frequencies. This increased detail of memory developed due to a loss of response to lower and higher frequency side-bands, without any change in the absolute magnitude of response to CS-band frequencies. These findings indicate that the sensory contents of associative memory can be revealed to become more specific, through temporal consolidation in the absence of non-sensory factors such as motivation and emotion.     

An interfering dot-probe task facilitates the detection of mock crime memory in a reaction time (RT)-based concealed information test

The present study aimed to test the hypothesis that an interfering task in the concealed information test will help the detection of concealed memory based on participants' behavioral performance (e.g. reaction time, error rate). Here, after participants enacted a mock crime, they were introduced to a concealed information test either with or without an interfering dot-probe task. Results showed that the RT-based pure-CIT (without interference) can detect concealed memory well above chance (AUC = .88). The detection efficiency was higher (AUC = .94) in the interference-CIT based on participants' performance of the interfering task. The findings suggested that the elevation of cognitive workload could possibly increase the detection efficiency of concealed memory based on behavioral measures.     

Impaired retention is responsible for temporal order memory deficits in mild cognitive impairment

Temporal order memory, or remembering the order of events, is critical for everyday functioning and is difficult for patients with mild cognitive impairment (MCI). It is currently unclear whether these patients have difficulty acquiring and/or retaining such information and whether deficits in these patients are in excess of “normal” age-related declines. Therefore, the current study examined age and disease-related changes in temporal order memory as well as whether memory load played a role in such changes. Young controls (n = 25), older controls (n = 34), and MCI patients (n = 32) completed an experimental task that required the reconstruction of sequences that were 3, 4, or 5 items in length both immediately after presentation (i.e., immediate recall) and again after a 10-min delay (i.e., delayed recall). During the immediate recall phase, there was an effect of age largely due to reduced performance at the two longest span lengths. Older controls and MCI patients only differed during the five span (controls > MCI). During the delayed recall, however, there were significant effects of both age and MCI regardless of span length. In MCI patients, immediate recall was significantly correlated with measures of executive functioning, whereas delayed recall performance was only related to other memory tests. These findings suggest that MCI patients experience initial temporal order memory deficits at the point when information begins to exceed working memory capacity and become dependent on medial temporal lobe functioning. Longer-term deficits are due to an inability to retain information, consistent with the characteristic medial temporal lobe dysfunction in MCI.     

Acute effects of alcohol on memory: Impact of emotional context and serial position

Although the amnestic effects of alcohol in humans are well known, its effects on emotional memory are unclear. In this study, using a randomized double-blind placebo-controlled design, we examine narrative emotional episodic memory in healthy human female volunteers (n = 32) who received either a single dose of alcohol (0.6 g/kg), or a placebo and then viewed neutral story elements presented in either a neutral or emotional context. Memory was tested for gist and detail of the neutral elements 3 days later in a surprise recognition test. Since alcohol modulates GABAergic neurotransmission and may exert its effects on emotion through the limbic system, we predicted that acute alcohol treatment would reduce the expected emotional memory-advantage for gist, leaving detail memory relatively unaffected. Furthermore, given previous findings showing that ‘primacy’ memory is enhanced by physiological arousal, we predicted that reduced arousal produced by alcohol would have the opposite effect and impair primacy memory relative to the middle or ‘recency’ sections of the narrative. Emotional arousal was expected to oppose this effect, so impaired primacy memory following alcohol was only expected in the neutral version of the narrative. Although there was a main effect of story phase (though not of story version), contrary to expectations, alcohol impaired primacy memory for emotionally encoded neutral material. The results suggest that under certain circumstances emotional context or physiological arousal make memories labile and susceptible to disruption through pharmacological manipulation during encoding.     

Intensive video gaming improves encoding speed to visual short-term memory in young male adults

The purpose of this study was to measure the effect of action video gaming on central elements of visual attention using Bundesen's (1990) Theory of Visual Attention.To examine the cognitive impact of action video gaming, we tested basic functions of visual attention in 42 young male adults. Participants were divided into three groups depending on the amount of time spent playing action video games: non-players (< 2 h/month, N = 12), casual players (4–8 h/month, N = 10), and experienced players (> 15 h/month, N = 20). All participants were tested in three tasks which tap central functions of visual attention and short-term memory: a test based on the Theory of Visual Attention (TVA), an enumeration test and finally the Attentional Network Test (ANT). The results show that action video gaming does not seem to impact the capacity of visual short-term memory. However, playing action video games does seem to improve the encoding speed of visual information into visual short-term memory and the improvement does seem to depend on the time devoted to gaming. This suggests that intense action video gaming improves basic attentional functioning and that this improvement generalizes into other activities. The implications of these findings for cognitive rehabilitation training are discussed.     

Does goal relevant episodic future thinking amplify the effect on delay discounting?

Delay discounting (DD) is the preference for smaller immediate rewards over larger delayed rewards. Research shows episodic future thinking (EFT), or mentally simulating future experiences, reframes the choice between small immediate and larger delayed rewards, and can reduce DD. Only general EFT has been studied, whereby people reframe decisions in terms of non-goal related future events. Since future thinking is often goal-oriented and leads to greater activation of brain regions involved in prospection, goal-oriented EFT may be associated with greater reductions in DD than general goal-unrelated EFT. The present study (n = 104, M_age = 22.25, SD = 3.42; 50% Female) used a between-subjects 2 × 2 factorial design with type of episodic thinking (Goal, General) and temporal perspective (Episodic future versus recent thinking; EFT vs ERT) as between factors. Results showed a significant reduction in DD for EFT groups (p < 0.001, Cohen’s d effect size = 0.89), and goal-EFT was more effective than general-EFT on reducing DD (p = 0.03, d = 0.64).     

The role of working memory and visual processing in prototype category learning

To investigate whether working memory and visual processing have the same role or different roles in A/B and A/not A prototype category learning, the present study adopted an A/B or A/not A category learning task in control and dual conditions. The results of Experiment 1 showed that an additional dual visual working memory task rather than a dual verbal working memory task reduced accuracy of the A/B task, whereas no dual tasks influenced accuracy of the A/not A task. The results of Experiment 2 revealed that an additional dual visual processing task impaired accuracy of the A/B task, whereas the dual visual processing task did not influence accuracy of the A/not A task. These results indicate that visual working memory and visual processing play different roles in A/B and A/not A prototype category learning, and support that these two types of prototype category learning are mediated by different memory systems.     

The association of physical activity to neural adaptability during visuo-spatial processing in healthy elderly adults: A multiscale entropy analysis

Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63 ± 1.31 years; female = 12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29 ± 1.20 years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition.     

Comparing neurocognitive impairment in schizophrenia and bipolar I disorder using the Screen for Cognitive Impairment in Psychiatry Scale

The purpose of this study was to compare the psychometric properties of the Screen for Cognitive Impairment in Psychiatry (SCIP) when applied to patients diagnosed with schizophrenia (n = 126) or bipolar I disorder (n = 76), and also to compare the cognitive impairment in both samples of patients and a control group (n = 83) using the SCIP and a complete neuropsychological battery. The SCIP is a scale intended to quickly and easily assess cognitive impairment in patients with severe psychiatric disorders. The results showed firstly that, in terms of internal consistency, temporal stability, dimensional structure, and criterion-referenced validity, the SCIP provides reliable and valid scores at an equivalent level in both schizophrenia and bipolar I disorder samples. Secondly, it showed that differential cognitive impairment between the two patient groups occurs only in verbal memory, although the effect size of the difference is small. Finally, compared with the control group, cognitive impairment was present at all levels in both groups of patients using both the SCIP and the neuropsychological battery, which indicates that the SCIP is a good screening tool for cognitive deficits in schizophrenia and bipolar and useful in clinical practice for healthcare professionals.     

Component analysis of simple span vs. complex span adaptive working memory exercises: A randomized,controlled trial

There has been growing interest in using adaptive training interventions such as Cogmed-RM to increase the capacity of working memory (WM), but this intervention may not be optimally designed. For instance, Cogmed-RM can target the primary memory (PM) component of WM capacity, but not the secondary memory (SM) component. The present study hypothesized that Cogmed-RM does not target SM capacity because the simple span exercises it uses may not cause a sufficient amount of information to be lost from PM during training. To investigate, we randomly assigned participants to either a standard (simple span; N = 31) or a modified (complex span; N = 30) training condition. The main findings showed that SM capacity did not improve, even in the modified training condition. Hence, the potency of span-based WM interventions cannot be increased simply by converting simple span exercises into complex span exercises.     

Will students pass a competitive exam that they failed in their dreams?

We tested whether dreams can anticipate a stressful exam and how failure/success in dreams affect next-day performance. We collected information on students’ dreams during the night preceding the medical school entrance exam. Demographic, academic, sleep and dream characteristics were compared to the students’ grades on the exam. Of the 719 respondents to the questionnaire (of 2324 total students), 60.4% dreamt of the exam during the night preceding it. Problems with the exam appeared in 78% of dreams and primarily involved being late and forgetting answers. Reporting a dream about the exam on the pre-exam night was associated with better performance on the exam (p = .01). The frequency of dreams concerning the exam during the first term predicted proportionally higher performance on the exam (R = 0.1, p = .01). These results suggest that the negative anticipation of a stressful event in dreams is common and that this episodic simulation provides a cognitive gain.     

Cognitive Load Undermines Thought Suppression in Acute Stress Disorder

Thought suppression studies demonstrate that attempts to suppress can be undermined by cognitive load. We report the first instance in which this has been tested experimentally in a sample of recently traumatized individuals. Individuals with and without acute stress disorder (ASD) were recruited following recent trauma and randomized to load or no load conditions (N = 56). They monitored intrusive memories during baseline, suppression, and think anything phases. The impact of suppression and load on self-reported intrusions, attention bias (dot-probe), and memory priming (word-stem task) was assessed. The ASD load group were less able to suppress memories (d = 0.32, CI₉₅ [− 0.15, 0.83], p = .088) than the ASD no load group (d = 0.63, CI₉₅ [0.08, 1.24], p < .001). In the think anything phase, the ASD load group reported more intrusions than the ASD no load or non-ASD groups (with and without load). No consistent findings were observed in relation to attentional bias. ASD load individuals exhibited stronger priming responses for motor vehicle accident and assault words than all other groups (ds between 0.35–0.73). Working memory did not moderate any outcomes of interest. The findings indicate that cognitive load interferes with suppression and may enhance access to trauma memories and associated material. The study extends previous research by demonstrating these effects for the first time in a clinical sample of recent survivors of trauma.     

Witnesses’ memories for lineup fillers postdicts their identification accuracy

Witnesses who have quick, automatic recognition experiences when viewing a lineup tend to make more accurate decisions than witnesses who engage in slower, more deliberative processes. A novel postdictor of identification accuracy is predicted from these findings: memories for lineup fillers should be stronger among inaccurate, rather than accurate, witnesses. Undergraduate students (N = 320) viewed a mock crime, made a lineup identification decision, and were given a surprise test for their memory for the lineup fillers. Consistent with predictions, better memories for lineup fillers postdicted mistaken identifications and the suspect's innocence. Information gain analyses showed that under some conditions, memory for lineup fillers provided as much information about the suspect's guilt as a lineup identification. Findings are consistent with the idea that postdictors of eyewitness accuracy are valuable to the extent that they measure the automaticity or deliberativeness of the witness's experience when viewing the lineup.     

SLV330, a cannabinoid CB1 receptor antagonist,ameliorates deficits in the T-maze,object recognition and Social Recognition Tasks in rodents

Cannabinoid CB₁ receptor (CB₁R) signaling has been suggested to play an important role in the regulation of memory and cognition. In the present study, our aim was to investigate whether the CB₁R antagonist SLV330 (doses ranging from 0.3 to 10 mg/kg, given orally, p.o.) could ameliorate impairments in distinct aspects of cognition using different disruption models in both mice and rats. Effects of SLV330 were tested on working memory deficits in the T-maze Continuous Alternation Task (T-CAT) in mice; episodic memory deficits in the Object Recognition Task (ORT) and Social Recognition Task (SRT) in rats. The acetylcholinesterase inhibitor (AChEI) donepezil (Aricept®, approved for symptomatic treatment of Alzheimer’s disease) and nicotine were used as reference compounds.SLV330 markedly improved aging and scopolamine-induced memory deficits in the T-CAT in mice with a lowest effective dose (LED) of 1 mg/kg p.o., while reversing the cognitive dysfunction induced by the N-methyl-d-aspartate (NMDA) antagonist dizocilpine (MK-801) only at the middle dose of 3 mg/kg. In the ORT, we have found that combined administration of subthreshold doses of SLV330 (1 mg/kg, p.o.) and the AChEI donepezil (0.1 mg/kg, p.o.), that had no discernable effects on performance when given alone, enhanced memory performance in Wistar rats with deficits induced by the muscarinic antagonist scopolamine, suggestive of additive synergistic effects of SLV330 and donepezil on cognitive impairment. Finally, SLV330 was found to have cognition enhancing properties in a time delay paradigm in the SRT at a LED dose of 3 mg/kg (p.o.).In conclusion, the CB₁R antagonist SLV330 was found to clearly improve memory in several preclinical models for cognitive impairment.     

Active sleep is associated with the face preference in the newborns who familiarized with a responsive face

Aim of this study was to investigate the preferential looking behaviour, subsequent to a familiarization task (8-min) with a previously responsive or motionless face, before and after a sleep cycle. Moreover, the role of the active sleep in memory consolidation of the responsive or motionless faces was explored. Hypotheses were that the newborns undergoing a motionless familiarization will exhibit a novelty effect (preference for the novel face) whereas the newborns undergoing a responsive familiarization will show a familiarity effect (preference for the known face) before and after the sleep cycle; moreover, the amount of active sleep will be associated with the looking time at the known face after a sleep cycle.Forty-five healthy full-term newborns were randomly assigned to two groups (group 1: motionless-familiarization and group 2: responsive-familiarization); in both groups newborns were video-recorded during four post-familiarization face-preference tasks, two of them performed before and two after a sleep cycle.During the pre-sleep-trials, there was not a significant preference for one face in both groups. During the post-sleep trials, the newborns showed a clear preference for the novel face. This effect was more evident in group 1. Only in group 2 there was a significant positive correlation between the active sleep duration and the looking duration at the known-face during the post-sleep trials (r = 0.41; p = 0.040). Multiple regression confirmed that only in the group 2 the total duration of the active sleep was associated with the looking duration at the known-face during the post-sleep trials (Adjusted R² = 0.13; β = 0.41; t = 2.2; p = 0.040).Findings showed that in newborns the face representation can be recalled after a sleep cycle. Moreover, the amount of the active sleep predicted the post-sleep looking toward the known-face only in the newborns who interactively familiarized with the face.     

Appearance-related teasing,body dissatisfaction,and disordered eating: A meta-analysis

A meta-analysis was conducted to determine the relationship between appearance and weight-based teasing and three outcome measures: body dissatisfaction, restrictive eating, and bulimic behaviors. Four meta-analyses were conducted. Fifty effect sizes (N = 10,618) resulted in a moderate effect size of .39 for the relationship between weight teasing and body dissatisfaction; 24 effect sizes (N = 7190) resulted in an effect size of .32 for the relationship between appearance teasing and body dissatisfaction; 20 effect sizes (N = 4792) resulted in an effect size of .35 for the relationship between weight teasing and dietary restraint; and 22 effect sizes (N = 5091) resulted in an effect size of .36 for the relationship between weight teasing and bulimic behaviors. Significant moderators that emerged were teasing measure type, publication type, study type, age group, and gender. The findings offer further support for the inclusion of strategies in body image and eating disorders’ prevention and intervention programs that focus on handling negative, appearance-related commentary.     

Employees’ work effort as a function of leader group prototypicality: the moderating role of team identification

The social identity model of organizational leadership (SIMOL; Hogg and van Knippenberg, 2003 was extended analyzing the degree of employees’ effort as individual outcome of leadership effectiveness. Two studies were conducted with Italian participants. Study 1 was a survey conducted with 68 employees of a medium size company. Results showed the significant two-way interaction effect of team identification × leader group prototypicality in predicting employees’ work effort. Study 2, including 124 students, was a 2 × 2 within subject design (team identification high vs. low × leader group prototypicality high vs. low) using scenarios. Results confirmed experimentally the causal relationship between such variables: subjects in condition of high team identification and high leader group prototypicality perceive leaders as more effective than the subjects in the other three conditions.