| 1. |
- Araújo, Susana, et al.
(författare)
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Lexical and sublexical orthographic processing: An ERP study with skilled and dyslexic adult readers.
- 2015
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Ingår i: Brain and Language. - : Elsevier BV. - 1090-2155 .- 0093-934X. ; 141, s. 16-27
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Tidskriftsartikel (refereegranskat)abstract
- This ERP study investigated the cognitive nature of the P1-N1 components during orthographic processing. We used an implicit reading task with various types of stimuli involving different amounts of sublexical or lexical orthographic processing (words, pseudohomophones, pseudowords, nonwords, and symbols), and tested average and dyslexic readers. An orthographic regularity effect (pseudowords-nonwords contrast) was observed in the average but not in the dyslexic group. This suggests an early sensitivity to the dependencies among letters in word-forms that reflect orthographic structure, while the dyslexic brain apparently fails to be appropriately sensitive to these complex features. Moreover, in the adults the N1-response may already reflect lexical access: (i) the N1 was sensitive to the familiar vs. less familiar orthographic sequence contrast; (ii) and early effects of the phonological form (words-pseudohomophones contrast) were also found. Finally, the later N320 component was attenuated in the dyslexics, suggesting suboptimal processing in later stages of phonological analysis.
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| 2. |
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| 3. |
- Bramao, Ines, et al.
(författare)
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Benefits and costs of context reinstatement in episodic memory : An ERP study
- 2017
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Ingår i: Journal of Cognitive Neuroscience. - : MIT Press - Journals. - 1530-8898 .- 0898-929X. ; 29:1, s. 52-64
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated context-dependent episodic memory retrieval. An influential idea in the memory literature is that performance benefits when the retrieval context overlaps with the original encoding context. However, such memory facilitation may not be driven by the encoding-retrieval overlap per se but by the presence of diagnostic features in the reinstated context that discriminate the target episode from competing episodes. To test this prediction, the encoding-retrieval overlap and the diagnostic value of the context were manipulated in a novel associative recognition memory task. Participants were asked to memorize word pairs presented together with diagnostic (unique) and nondiagnostic (shared) background scenes. At test, participants recognized the word pairs in the presence and absence of the previously encoded contexts. Behavioral data show facilitated memory performance in the presence of the original context but, importantly, only when the context was diagnostic of the target episode. The electrophysiological data reveal an early anterior ERP encoding-retrieval overlap effect that tracks the cost associated with having nondiagnostic contexts present at retrieval, that is, shared by multiple previous episodes, and a later posterior encoding-retrieval overlap effect that reflects facilitated access to the target episode during retrieval in diagnostic contexts. Taken together, our results underscore the importance of the diagnostic value of the context and suggest that context-dependent episodic memory effects are multiple determined.
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| 4. |
- Bramao, Ines, et al.
(författare)
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Electrophysiological signatures revealing the temporal dynamics of episodic retrieval
- 2022
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Konferensbidrag (refereegranskat)abstract
- Episodic memory enables mental time travel, allowing us to relive specific, personally experienced events tied in time and place. This feat of human memory is considered to be dependent on the reinstatement of the cortical patterns that were active at the time of encoding. A growing body of recent literature has provided support for this idea by showing that retrieval success co-varies with the neural encoding patterns being reinstated at the time of retrieval. In this presentation, we will discuss findings from multivariate pattern analysis of electrophysiological data revealing the temporal dynamics of such reinstatement during retrieval and its consequences for episodic remembering. First, we will discuss both benefits and costs of cortical pattern reinstatement. Accumulating evidence has shown that memory typically benefits when the neural patterns established during encoding are reinstated during retrieval. However, our data show that reinstatement can also have detrimental effects on later episodic remembering depending on which aspects of the event are called-for. Next, we will show that contextual background features of an encoding episode are reinstated during selective retrieval even when such information is task-irrelevant. These data elucidate that context reinstatement tracks retrieval competition between similar episodes and interference resolution. Combined, our data elucidate the temporal dynamics of episodic remembering and shed new light on encoding and retrieval interactions in episodic memory.
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| 5. |
- Bramao, Ines, et al.
(författare)
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Encoding contexts are incidentally reinstated during competitive retrieval and track the temporal dynamics of memory interference
- 2022
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Ingår i: Cerebral Cortex. - : Oxford University Press (OUP). - 1460-2199 .- 1047-3211. ; 32:22, s. 5020-5035
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Tidskriftsartikel (refereegranskat)abstract
- The ability to remember an episode from our past is often hindered by competition from similar events. For example, if we want to remember the article a colleague recommended during the last lab-meeting, we may need to resolve interference from other article recommendations from the same colleague. This study investigates if the contextual features specifying the encoding episodes are incidentally reinstated during competitive memory retrieval. Competition between memories was created through the AB/AC interference paradigm. Individual word-pairs were presented embedded in a slowly drifting real-word like context. Multivariate pattern analysis (MVPA) of high temporal-resolution electroencephalographic (EEG) data was used to investigate context reactivation during memory retrieval. Behaviorally, we observed proactive (but not retroactive) interference; that is, performance for AC competitive retrieval was worse compared to a control DE non-competitive retrieval, whereas AB retrieval did not suffer from competition. Neurally, proactive interference was accompanied by an early reinstatement of the competitor context and interference resolution was associated with the ensuing reinstatement of the target context. Together, these findings provide novel evidence showing that the encoding contexts of competing discrete events are incidentally reinstated during competitive retrieval and that such reinstatement tracks retrieval competition and subsequent interference resolution.
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| 6. |
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| 7. |
- Bramao, Ines, et al.
(författare)
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Mental reinstatement of encoding context improves episodic remembering
- 2017
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Ingår i: Cortex. - : Elsevier BV. - 0010-9452. ; 94, s. 15-26
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates context-dependent memory retrieval. Previous work has shown that physically re-experiencing the encoding context at retrieval improves memory accessibility. The current study examined if mental reconstruction of the original encoding context would yield parallel memory benefits. Participants performed a cued-recall memory task, preceded either by a mental or by a physical context reinstatement task, and we manipulated whether the context reinstated at retrieval overlapped with the context of the target episode. Both behavioral and electrophysiological measures of brain activity showed strong encoding-retrieval (E-R) overlap effects, with facilitated episodic retrieval when the encoding and retrieval contexts overlapped. The electrophysiological E-R overlap effect was more sustained and involved more posterior regions when context was mentally compared with physically reinstated. Additionally, a time-frequency analysis revealed that context reinstatement alone engenders recollection of the target episode. However, while recollection of the target memory is readily prompted by a physical reinstatement, target recollection during mental reinstatement is delayed and depends on the gradual reconstruction of the context. Taken together, our results show facilitated episodic remembering also when mentally reinstating the encoding context; and that such benefits are supported by both shared and partially non-overlapping neural mechanisms when the encoding context is mentally reconstructed as compared with physically presented at the time of retrieval.
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| 8. |
- Bramao, Ines, et al.
(författare)
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Neural correlates of mental context reinstatement supporting episodic memory retrieval
- 2016
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Konferensbidrag (refereegranskat)abstract
- This study investigated if mental reinstatement of an encoding context during retrieval increases memory accessibility. Participants performed a cued-recall memory task where the overlap between encoding and retrieval context and the nature of context reinstatement (mental versus physical) were manipulated. Memory performance improved when the encoding-retrieval context overlapped in a comparable way for mental and physical context reinstatement. However, compared to physical reinstatement, mental reinstatement was characterized by later and more sustained ERP effects. Together, our results suggest that the access to episodic memories can be facilitated also by mentally reinstating the encoding context, and furthermore that such benefits may be supported by processes differently engaged than when the encoding context is physically re-presented at the time of retrieval.
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| 9. |
- Bramao, Ines, et al.
(författare)
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Neural pattern classification reveals the temporal dynamics of competitive memory retrieval
- 2019
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Konferensbidrag (refereegranskat)abstract
- Resolution of interference between competing memories is often critical for remembering. This study employed multivariate pattern analysis (MVPA) of electroencephalographic (EEG) data to investigate the temporal dynamics of retrieval competition and competition resolution. Competition between memories was created through the AB/AC interference paradigm. Memory retrieval of competitive AB and AC cue-associate word pairs was compared with non-competitive DE word pairs. Behavioural results showed worse memory performance for AC compared with DE word pairs, but comparable performance for AB and DE word pairs, revealing proactive without retroactive interference. Critically, the AB, AC and DE word pairs were encoded embedded in a movie with a distinct theme (first-person perspective of underwater, forest, and city environments). We trained classifiers to discriminate patterns of brain activity associated with the movies at encoding. The classifiers were later applied during memory retrieval to track memory reactivation. In an early cue time window, where only the word cue was presented (i.e. A or D), we observed classification performance for non-competitive retrieval, revealing target reactivation, but no classification for competitive retrieval, presumably due to the simultaneous reactivation of target and competitor memories. In a following probe time window, when participants were given a first-letter probe to retrieve the target word (i.e. B/C/E), we observed classification performance ~700 ms after probe onset for the competitive retrieval, revealing the time course of competition resolution. Importantly, classification accuracy in this late time window co-varied with memory performance, that is, with the resolution of proactive interference. This study offers novel insights into the time course of memory competition and competition resolution.
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| 10. |
- Bramao, Ines, et al.
(författare)
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Neural pattern classification tracks transfer-appropriate processing in episodic memory
- 2018
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Ingår i: eNeuro. - 2373-2822.
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Tidskriftsartikel (refereegranskat)abstract
- The transfer-appropriate processing (TAP) account holds that episodic memory depends on the overlap between encoding and retrieval processing. In the current study, we employed multivariate pattern analysis (MVPA) of electroencephalography to examine the relevance of spontaneously engaged visual processing during encoding for later retrieval. Human participants encoded word- picture associations, where the picture could be a famous face, a landmark, or an object. At test, we manipulated the retrieval demands by asking participants to retrieve either visual or verbal information about the pictures. MVPA revealed classification between picture categories during early perceptual stages of encoding (∼170 ms). Importantly, these visual category-specific neural patterns were predictive of later episodic remembering, but the direction of the relationship was contingent on the particular retrieval demand of the memory task: a benefit for the visual and a cost for the verbal. A reinstatement of the category-specific neural patterns established during encoding was observed during retrieval, and again the relationship with behavior varied with retrieval demands. Reactivation of visual representations during retrieval was associated with better memory in the visual task, but with lower performance in the verbal task. Our findings support and extend the TAP account by demonstrating that processing of particular aspects during memory formation can also have detrimental effects on later episodic remembering when other aspects of the event are called-for and shed new light on encoding and retrieval interactions in episodic memory.
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