Episodic representations support early semantic learning: evidence from midazolam induced amnesia

Current controversy exists regarding the role of episodic representations in the formation of long-term semantic memories. Using the drug midazolam to induce temporary amnesia we tested participants' memories for newly learned facts in a semantic cue condition or an episodic and semantic cue condition. Following midazolam administration, memory performance was superior in the episodic and semantic condition, suggesting early semantic learning is supported by episodic representations.     

合体字与复合词中联结编码和项目编码的关系

本研究通过考察合体字和复合词加工过程中联结记忆和项目记忆的变化,探究了在将不同项目绑定为整体的过程中联结编码和项目编码间的关系,并结合脑电技术比较了合体字和复合词的加工过程在神经机制上的差异。行为结果显示:与不能组成字或词的编码条件相比,合体字和复合词编码条件下的联结记忆成绩有显著提升,且项目记忆成绩没有下降;与复合词编码相比,合体字编码条件下的联结记忆和项目记忆成绩都显著更好。脑电结果显示:复合词编码时晚期负成分(LNC)主要位于额区且发生较早,而合体字编码时的LNC主要位于枕区且发生更晚;合体字编码比复合词编码在α/β频段的神经振荡去同步化更强。这些结果表明,将不同项目绑定为整体的操作可以强化大脑对联结信息的加工,同时不会损害对项目的加工,支持了“只有收益”的观点。本研究也从实证的角度为汉语学习材料的编排提供了参考。     

Muscimol Induces Retrograde Amnesia for Changes in Reward Magnitude

These experiments examined the effect of the GABA_A, agonist, muscimol (MUS), on memory for changes in reward magnitude. In Experiment 1 rats were trained to run a straight alley for either a large or small food reward. After reaching asymptotic performance rats in the high reward group were shifted to the small food reward. Half the animals received 1.0 or 3.0 mg/kg (ip) of MUS or the equivalent volume of saline immediately after training. Shifted training continued for 3 more days and no further injections were given. Shifted saline animals displayed an increase in response latencies compared to unshifted controls with a sharp peak on the day after the shift. Shifted MUS receiving 1.0 mg/kg performed comparably to shifted saline animals. In contrast, shifted MUS animals receiving 3.0 mg/kg displayed performance comparable to shifted saline animals on the day of the shift but displayed a sharp increase in response latencies on the second day after the shift. These findings indicate that post-training systemic MUS injections delay the peak increase in response latencies and suggest that MUS induces retrograde amnesia for reward reduction. Experiment 2 examined the effect of MUS on the memory of a reward increase. Rats were first trained as in Experiment 1 and rats under the high reward condition were then shifted to the small reward. On the next training session, the large food reward was reinstated. Immediately after the session all animals were injected with saline or 3.0 mg/kg of MUS. The large food reward was continued for the remainder of training and no further injections were given. On the following session, the performance of the shifted saline animals was comparable to that of the unshifted controls while shifted MUS animals displayed significantly higher response latencies. The findings that MUS prevented the reduction in response latencies seen in saline-injected animals suggest that MUS also induces retrograde amnesia for reward increases.     

The effect of cognitive reappraisal on long‐term emotional experience and emotional memory

One's ability to properly regulate emotion is critical to psychological and physical well‐being. Among various strategies to regulate emotion, cognitive reappraisal has been shown to modulate both emotional experience and emotional memory. However, most studies of reappraisal have focused on reappraisal of negative situations, with reappraisal of positive emotion receiving considerably less attention. In addition, the effects of reappraisal on emotional reactions to stimuli are typically only assessed either immediately or after a short delay, and it remains unclear whether reappraisal effects persist over longer time periods. We investigated the effect of cognitive reappraisal on emotional reactions and long‐term episodic memory for positive and negative stimuli. Men and women viewed emotionally negative, positive, and neutral pictures while they were instructed to either increase, decrease, or maintain the initial emotional reactions elicited by the pictures. Subjective ratings of emotional valence and arousal were assessed during the regulation task and again after 1 week. Memory for the pictures was assessed with free recall. Results indicated that pictures accompanied by instructions to increase emotion were better recalled than pictures reappraised to decrease emotion. Modulation of emotional arousal elicited by stimuli persisted over a week, but this effect was observed only for men. These findings suggest that cognitive reappraisal can have long‐lasting effects on emotional reactions to stimuli. However, the sex differences observed for the effects of reappraisal on emotional reactions highlight the importance of considering individual differences in the effects of regulation.     

Mental comparisons involving abstract attributes

Adult subjects in two experiments were presented pairs of stimuli that differed in varying degree on an abstract semantic attribute, and were required to choose the one with the higher value on the given dimension. Subjects in Experiment 1 chose the more pleasant member of a pair of pictures, concrete nouns, or abstract nouns. Those in Experiment 2, presented a pair of pictures or concrete nouns, chose the one whose referent had the higher monetary value. Theoretical interest centered on the effects of semantic distance, stimulus mode, and individual differences in imagery and verbal ability on choice time. In both experiments, response times (1) decreased with increases in semantic distance, (2) were faster for pictures than words (and for concrete than abstract words in Experiment 1), and (3) were faster for high- than for lowimagery participants. The results are completely consistent with a dual-coding (image vs. verbal) interpretation: Pleasantness and value, though conceptually abstract, are attributes of things rather than words, and they are accordingly represented in and processed by a system specialized for dealing with nonverbal information.     

认知负载对基于动机的情绪刺激加工的影响

结合数数任务和情绪flanker任务,探究不同认知负载条件下,高低趋近动机对情绪刺激加工的影响。结果发现：高负载组中,高趋近动机条件下,对积极目标刺激的反应显著快于消极目标刺激;低趋近动机条件下,对消极目标刺激的反应显著快于积极目标刺激。且高负载组中,各条件下的反应大多都显著慢于低负载组。低负载组中没有发现各条件之间的差异。结果表明,高负载条件下,高趋近动机促进了积极情绪刺激的加工,低趋近动机促进了消极情绪刺激的加工,高负载在一定程度上阻碍了情绪刺激的加工。     

French norms of imagery for pictures, for concrete and abstract words]

This paper deals with French norms for mental image versus picture agreement for 138 pictures and the imagery value for 138 concrete words and 69 abstract words. The pictures were selected from Snodgrass et Vanderwart's norms (1980). The concrete words correspond to the dominant naming response to the pictorial stimuli. The abstract words were taken from verbal associative norms published by Ferrand (2001). The norms were established according to two variables: 1) mental image vs. picture agreement, and 2) imagery value of words. Three other variables were controlled: 1) picture naming agreement; 2) familiarity of objects referred to in the pictures and the concrete words, and 3) subjective verbal frequency of words. The originality of this work is to provide French imagery norms for the three kinds of stimuli usually compared in research on dual coding. Moreover, these studies focus on figurative and verbal stimuli variations in visual imagery processes.     

认知负载对基于动机的情绪刺激加工的影响

结合数数任务和情绪flanker任务,探究不同认知负载条件下,高低趋近动机对情绪刺激加工的影响。结果发现：高负载组中,高趋近动机条件下,对积极目标刺激的反应显著快于消极目标刺激;低趋近动机条件下,对消极目标刺激的反应显著快于积极目标刺激。且高负载组中,各条件下的反应大多都显著慢于低负载组。低负载组中没有发现各条件之间的差异。结果表明,高负载条件下,高趋近动机促进了积极情绪刺激的加工,低趋近动机促进了消极情绪刺激的加工,高负载在一定程度上阻碍了情绪刺激的加工。     

Storage and retrieval properties of dual codes for pictures and words in recognition memory.

Storage and retrieval properties of pictures and words were studied within a recognition memory paradigm. Storage was manipulated by instructing subjects either to image or to verbalize to both picture and word stimuli during the study sequence. Retrieval was manipulated by representing a proportion of the old picture and word items in their opposite form during the recognition test (i.e., some old pictures were tested with their corresponding words and vice versa). Recognition performance for pictures was identical under the two instructional conditions, whereas recognition performance for words was markedly superior under the imagery instruction condition. It was suggested that subjects may engage in dual coding of simple pictures naturally, regardless of instructions, whereas dual coding of words may occur only under imagery instructions. The form of the test item had no effect on recognition performance for either type of stimulus and under either instructional condition. However, change of form of the test item markedly reduced item-by-item correlations between the two instructional conditions. It is tentatively proposed that retrieval is required in recognition, but that the effect of a form change is simply to make the retrieval process less consistent, not less efficient.     

Repetition priming of words and pseudowords in divided attention and in amnesia

Repetition priming of novel stimuli (pseudowords) and stimuli with preexisting representations (words) was compared in two experiments. In one, 19 normal male subjects performed a lexical decision task with either focused or divided attention. In another, lexical decision performance was compared between 8 male Korsakoff patients and 8 alcoholic control subjects. In control conditions, repetition speeded responses to both stimulus types. Experimental conditions that minimized the contribution of episodic memory to task performance eliminated reaction time priming for pseudowords but not for words. However, in these same conditions, repetition increased the likelihood that pseudowords would be incorrectly classified. These results indicate that preserved repetition priming effects in amnesia do not solely reflect activation of representations in semantic memory.     

Nonconscious priming after 17 years: invulnerable implicit memory?

Individuals who saw pictures for 1 to 3 s in the laboratory were tested 17 years later by mail. Identification rates were significantly higher for fragments from these previously exposed targets than for novel fragments, whereas the same stimuli evoked no differences in control groups that had not been previously exposed to the pictures. Priming--the memorial advantage conferred by prior perceptual experience--was stable over the years (r= .51). Priming was dissociated from episodic memory, in that it was present even in subjects who reported no conscious recollection of their participation in the original laboratory session. These findings suggest that the perceptual representation system is an invulnerable memory system functioning below conscious awareness.     

Memory deficits in early infantile autism: some similarities to the amnesic syndrome.

Autistic children were compared with control children on tasks in which retention was tested by different methods. In three tests of recall, using named pictures, written words and spoken words as test stimuli, autistic children were impaired in comparison with age-matched normal children and with controls matched for verbal ability. In one test of forced-choice recognition of pictures, autistic children were impaired in comparison with ability-matched controls. In three tests of cued recall, using named pictures, written words and spoken words as test stimuli, and acoustic, graphemic and semantic cues, autistic children were not impaired in comparison with normal age-matched controls. In one test of paired-associate learning using non-related word pairs as test stimuli autistic children were not impaired in comparison with normal age-matched controls. These experimental paradigms were similar to some that have been used to investigate the amnesic syndrome in man. Thus findings on paired-associate learning differ in autistic and amnesic subjects, but findings on recall, recognition and cued recall are comparable. A possible parallel between autism and amnesia is discussed.     

Visual effects in picture and word categorization

Two experiments are reported in which participants categorized stimuli as belonging or not belonging to the category of fruits. Blocks of pictures and words were used, with items referring to exemplars having either high or low intercategory visual similarity and/or semantic relatedness. For both pictures and words, response time was longer in the semantically related conditions than in the unrelated condition. Furthermore, there was a strong effect of visual similarity for pictures but not for words when semantic relatedness was held constant: Participants took longer to classify pictures of fruits when these were mixed with visually similar vegetables than when they were mixed with visually dissimilar vegetables. Reducing the stimulus visibility by adding a dot pattern had an additive effect for words but an interactive effect for pictures. The results are explained in terms of a unique locus for category decisions about pictures and words.     

Preserved learning of novel information in amnesia: Evidence for multiple memory systems

Four of five patients with marked global amnesia, and others with new learning impairments, showed normal processing facilitation for novel stimuli (nonwords) and/or for familiar stimuli (words) on a word/nonword (lexical) decision task. The data are interpreted as a reflection of the learning capabilities of in-line neural processing stages with multiple, distinct, informational codes. These in-line learning processes are separate from the recognition/recall memory impaired by amygdalohippocampal/dosomedial thalamic damage, but probably supplement such memory in some tasks in normal individuals. Preserved learning of novel information seems incompatible with explanations of spared learning in amnesia that are based on the episodic/semantic or memory/habit distinctions, but is consistent with the procedural/declarative hypothesis.     

Theoretical analysis of the cognitive processing of lexical and pictorial stimuli: reading, naming, and visual and conceptual comparisons

This article reviews the research literature on the differences between word reading and picture naming. A theory for the visual and cognitive processing of pictures and words is then introduced. The theory accounts for slower naming of pictures than reading of words. Reading aloud involves a fast, grapheme-to-phoneme transformation process, whereas picture naming involves two additional processes: (a) determining the meaning of the pictorial stimulus and (b) finding a name for the pictorial stimulus. We conducted a reading-naming experiment, and the time to achieve (a) and (b) was determined to be approximately 160 ms. On the basis of data from a second experiment, we demonstrated that there is no significant difference in time to visually compare two pictures or two words when size of the stimuli is equated. There is no difference in time to make the two types of cross-modality conceptual comparisons (picture first, then word, or word first, then picture). The symmetry of the visual and conceptual comparison results supports the hypothesis that the coding of the mind is neither intrinsically linguistic nor imagistic, but rather it is abstract. There is a potent stimulus size effect, equal for both pictorial and lexical stimuli. Small stimuli take longer to be visually processed than do larger stimuli. For optimal processing, stimuli should not only be equated for size, but should subtend a visual angle of at least 3 degrees. The article ends with the presentation of a mathematical theory that jointly accounts for the data from word-reading, picture-naming visual comparison, and conceptual-comparison experiments.     

Does the generation effect occur for pictures?

The generation effect is the finding that self-generated stimuli are recalled and recognized better than read stimuli. The effect has been demonstrated primarily with words. This article examines the effect for pictures in two experiments: Subjects named complete pictures (name condition) and fragmented pictures (generation condition). In Experiment 1, memory was tested in 3 explicit tasks: free recall, yes/no recognition, and a source-monitoring task on whether each picture was complete or fragmented (the complete/incomplete task). The generation effect was found for all 3 tasks. However, in the recognition and source-monitoring tasks, the generation effect was observed only in the generation condition. We hypothesized that absence of the effect in the name condition was due to the sensory or process match effect between study and test pictures and the superior identification of pictures in the name condition. Therefore, stimuli were changed from pictures to their names in Experiment 2. Memory was tested in the recognition task, complete/incomplete task, and second source-monitoring task (success/failure) on whether each picture had been identified successfully. The generation effect was observed for all 3 tasks. These results suggest that memory of structural and semantic characteristics and of success in identification of generated pictures may contribute to the generation effect.     

无意识信息加工中的“完型”——无意识捆绑假说的新证据

采用连续闪烁范式(Continuous Flash Suppression,CFS)考察了无意识状态下完型能否发生.研究通过2(线条完整性)×2(意义破坏)×2(熟悉性)的被试内实验设计考察了8种条件下图片的突破抑制时间(Suppression Time,ST).结果发现:线条完整和意义未破坏的图片能更快地克服噪音图片的抑制进入意识;熟悉性不影响突破抑制时间.重要的是,不完整的图片也可以出现意义破坏效应.这表明即使在被抑制的状态下,不完整图形的信息也能够传达至与完型相关的高级视觉区域形成客体表征.研究为无意识捆绑假说(The Unconscious Binding Hypothesis)提供了新的实验证据.     

Do you remember where sounds,pictures and words came from? The role of the stimulus format in object location memory

Contrasting results in visual and auditory spatial memory stimulate the debate over the role of sensory modality and attention in identity-to-location binding. We investigated the role of sensory modality in the incidental/deliberate encoding of the location of a sequence of items. In 4 separated blocks, 88 participants memorised sequences of environmental sounds, spoken words, pictures and written words, respectively. After memorisation, participants were asked to recognise old from new items in a new sequence of stimuli. They were also asked to indicate from which side of the screen (visual stimuli) or headphone channel (sounds) the old stimuli were presented in encoding. In the first block, participants were not aware of the spatial requirement while, in blocks 2, 3 and 4 they knew that their memory for item location was going to be tested. Results show significantly lower accuracy of object location memory for the auditory stimuli (environmental sounds and spoken words) than for images (pictures and written words). Awareness of spatial requirement did not influence localisation accuracy. We conclude that: (a) object location memory is more effective for visual objects; (b) object location is implicitly associated with item identity during encoding and (c) visual supremacy in spatial memory does not depend on the automaticity of object location binding.     

Retrieval of Episodic Information From Memory: Comparisons Among 3- and 4-Year-Olds, 7- and 8-Year-Olds,and Adults

Young children's and adults' recall of episodic information was explored in 4 experiments. The task required participants to recall a target noun presented as the last item of a 4-noun string of related (either categorically or thematically) or unrelated words. Providing all 3 preceding nouns or a subset of them cued recall. Experiment 1 found that 7- and 8-year-old children's recall was better with pictures as opposed to text, and children showed performance equal to adults with thematically related pictorial stimuli. Using pictorial stimuli, Experiment 2 showed that the number of cues present at retrieval affected 7- and 8-year-olds' recall. Experiments 3 and 4 tested recall of episodic information in 3- and 4-year-olds using pictorial stimuli. The results suggested that young children also have access to episodic information in memory and the number of cues present at retrieval influenced recall. The findings are discussed in the context of children's memory for events.     

An increase in stimulus arousal has differential effects on the processing speed of pleasant and unpleasant stimuli

The arousal value of a stimulus influences its salience, whereby higher arousal should lead to faster processing. However, in previous research, participants consistently made faster valence judgments for low arousal, pleasant stimuli than for high arousal, pleasant stimuli. The speed of valence and arousal judgments for pictures and words were investigated in three experiments. Valence judgments were faster for low arousal than for high arousal pleasant pictures and for high arousal than for low arousal unpleasant pictures and words. Moreover, arousal judgments were faster for low arousal than high arousal pleasant and for high arousal than low arousal unpleasant pictures and words. The current research confirms that the impact of valence and arousal on processing speed does not reflect on the labels (valence versus arousal) used when recording speeded judgments. Similarly to valence, stimulus arousal interacts differentially with the evaluation of pleasant and unpleasant stimuli producing a processing advantage for high arousal, unpleasant stimuli but not high arousal, pleasant stimuli.