| 1. |
- Stenberg, Georg, et al.
(författare)
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Conceptual and perceptual memory: Retrieval orientations reflected in event-related potentials
- 2006
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Ingår i: Acta Psychologica. - : Elsevier BV. - 1873-6297 .- 0001-6918. ; 122:2, s. 174-205
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Tidskriftsartikel (refereegranskat)abstract
- In memory retrieval, search can be guided by mental sets towards different subsets of the available evidence. Such retrieval orientations have been suggested to leave an imprint on event-related potentials (ERPs). The present study aimed at characterizing orientations towards perceptual and conceptual evidence in a recognition task, where pictures and words were studied. In the recognition test, items were presented in either the same format as at study or in the opposite format. A between-subjects manipulation modified the task, instructing an Exclusion group to endorse only items that preserved their format from study, and an Inclusion group to endorse both formats of a studied item. It was hypothesized that exclusion instructions would instil a perceptual and inclusion instructions a conceptual orientation. As a corollary, instructions were expected to dissociate the high end from the low end of the picture word mirror effect. This expectation was confirmed in a behavioural experiment. In an ERP experiment, retrieval orientations were examined in their effects on correct rejections of new pictures and words. Confirming earlier findings [Hornberger, M., Morcom, A. M., & Rugg, M. D. (2004). Neural correlates of retrieval orientation: effects of study-test similarity. Journal of Cognitive Neuroscience, 16(7), 1196-1210], a perceptual orientation was accompanied by more positive-going amplitudes over widespread areas. The difference was larger for pictures than for words, supporting behavioural evidence that new pictures are more easily rejected on perceptual grounds than are new words. The Exclusion group showed no ERP evidence of cross-format old-new effects, despite reaction times indicative of involuntary conceptual recognition. The results indicate that perceptual and conceptual retrieval orientations imprint distinct signatures on ERPs. They further suggest that the examined old-new effects in ERPs are mainly linked to voluntary aspects of memory, even in a task where involuntary memory exerts effects on reaction times.
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| 2. |
- Stenberg, Georg, et al.
(författare)
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"Do you see Yonder cloud?" - On priming concepts, a new test, and a familiar outcome. Reply to Lucas et al. : "Familiarity or conceptual priming? Good question! Comment on Stenberg, Hellman, Johansson, and Rosén (2009)"
- 2010
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Ingår i: Journal of Cognitive Neuroscience. - : MIT Press - Journals. - 0898-929X .- 1530-8898. ; 22:4, s. 618-620
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Tidskriftsartikel (refereegranskat)abstract
- Lucas, Voss, and Paller sympathize with our intentions but disagree with our findings. They argue that a relation between frequency and conceptual priming may have been obscured by methodological details in our second experiment, therefore failing to complete a bridge between conceptual priming and FN400 with name frequency as the mediator. However, renewed inspections of our experiment and a new additional experiment, designed to meet the objections, fail to find any role for name frequency in conceptual priming and therefore re-establish the dissociation of priming and the FN400. On closer inspection, our differing views seem to derive from different interpretations of the term "concept."
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| 3. |
- Stenberg, Georg, et al.
(författare)
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Familiarity or conceptual priming – event-related potentials in name recognition
- 2009
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Ingår i: Journal of Cognitive Neuroscience. - : MIT Press - Journals. - 1530-8898 .- 0898-929X. ; 21:3, s. 447-460
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Tidskriftsartikel (refereegranskat)abstract
- Recent interest has been drawn to the separate components of recognition memory, as studied by event-related potentials (ERPs). In ERPs, recollection is usually accompanied by a late, parietal positive deflection. An earlier, frontal component has been suggested to be a counterpart, accompanying recognition by familiarity. However, this component, the FN400, has alternatively been suggested to reflect a form of implicit memory, conceptual priming. The present study examined the ERP components of recognition memory using an episodic memory task with a stimulus material consisting of names, half of which were famous. Along a different dimension, the names varied in how rare or common they were. These dimensions, frequency and fame, exerted powerful effects on memory accuracy, and dissociated the two recognition processes, such that frequency gave rise to familiarity and fame fostered recollection, when the receiver operating characteristics data were analyzed with Yonelinas' dual-process signal detection model. The ERPs corresponded fully to the behavioral data because frequency affected the frontal component exclusively, and fame affected the parietal component exclusively. Moreover, a separate behavioral experiment showed that conceptual priming was sensitive to fame, but not to frequency. Our data therefore indicate that the FN400 varies jointly with familiarity, but independently of conceptual priming.
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| 4. |
- Stenberg, Georg, et al.
(författare)
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Semantic Priming Effects in a Second Language: An Event-Related Potential Study
- 2004
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Ingår i: Bulletin of the Psychonomic Society. - 0090-5054. ; 9:Nov Abstract Supplement, s. 105-105
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Konferensbidrag (refereegranskat)abstract
- This study addressed the question whether the second language (L2) of bilinguals can access conceptual memory as directly as their first language (L1). Swedish undergraduates, with English as their second language, performed two tasks in both L1 and L2. Exp. 1 used a picture-name verification task, where pictures induced automatic semantic priming. Exp. 2 used a category-exemplar verification task, where pictures induced strategic priming. The primary measure was reduction of the N400 amplitude in the ERP. Experiment 1 showed a fronto-central priming effect that did not differ between L1 and L2 in amplitude, topographical distribution, or peak latency. Experiment 2 showed a different, centro-parietal priming effect that was similar in amplitude between L1 and L2, but differed in peak latency, and lateral distribution. The study indicates that L2 provides direct automatic access to conceptual memory, although strategic use may recruit partly different neuronal resources in L2 than in L1.
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| 5. |
- Stenberg, Georg, et al.
(författare)
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Perceptual and conceptual encoding in an ERP memory task
- 2003
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Mixed lists of pictures and words (concrete nouns) were studied for a subsequent recognition task. In the recognition block, pictures and words designating previously studied pictures and words appeared in a completely crossed fashion, mixed with distractors. E.g. if a picture of a horse had been studied, either the picture or the word "horse" could appear in the test. Two groups of participants (12 persons in each) were given different instructions. In the exclusion group, instructions were to endorse as old only those items where format (picture/word) was preserved. In the inclusion group, instructions were to endorse both formats of a previously studied item. The purpose of this manipulation was to encourage a relative emphasis on perceptual characteristics in the exclusion group, and a predominance of conceptual encoding in the inclusion group. An added objective was to assess the extent to which the two stimulus formats invite perceptual or conceptual processing. Event-related potentials recorded during study were examined as to mean amplitudes in the 400-800 ms range. Amplitudes were higher for the exclusion group compared to the inclusion group over posterior areas, indicating perceptual processing. Conversely, the inclusion group exhibited higher amplitudes over frontal and temporal areas, indicating conceptual processing.
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| 6. |
- Stenberg, Georg, et al.
(författare)
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Using a second language : semantic priming effects on the N400
- 2004
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Ingår i: Psychophysiology. - : Wiley. - 0048-5772 .- 1469-8986.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Some controversy has surrounded the question whether the second language (L2) of bilinguals can access conceptual memory as directly as their first language (L1). It has been proposed that an early age of acquisition and a high degree of proficiency are necessary for direct conceptual access. In the present study, Swedish undergraduates, with English as their second language, and a relatively late (9 yrs) age of acquisition, performed two word processing tasks in both L1 and L2. Exp. 1 used a picture-name verification task, where pictures induced automatic semantic priming. Exp. 2 used a category-exemplar verification task, where pictures again induced semantic priming, although in this case of a strategic kind. In both Exp. 1 (n = 22) and Exp. 2 (n = 23), the primary measure of semantic priming was reduction of the N400 amplitude in the ERP. Exp. 1 (automatic priming) showed a fronto-central priming effect that was indistinguishable in L1 and L2, as to amplitude, topographical distribution, and peak latency,although onset was somewhat earlier in L1. The effects of priming on reaction time (RT) were also parallel in L1 and L2. Exp. 2 (strategic priming) showed a different, centro-parietal priming effect that was similar in amplitude between L1 and L2, but differed in peak latency, and lateral distribution between languages. Also, the language factor interacted with priming in its effects on RT. The study indicates that L2 provides direct automatic access to conceptual memory, although strategic use of it may recruit partly different neuronal resources in L2 than in L1.
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| 7. |
- Wendt, Peter E., et al.
(författare)
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Ethanol reduces asymmetry of visual rCBF responses
- 1994
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications Inc.. - 0271-678X .- 1559-7016. ; 14:6, s. 963-973
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Tidskriftsartikel (refereegranskat)abstract
- Visual regional CBF (rCBF) responses were measured in 10 healthy male subjects before and after an ethanol dose of 1 g/kg body weight. This dose induces well-established cerebral vasodilatation. However, significant bilateral occipital increases were found in both conditions. Apparently, the coupling between neuronal activity and rCBF is preserved following ethanol. The occipital and posterior parietal flow increases were, however, larger on the right than the left side in the sober state. During inebriation the asymmetry disappeared, possibly representing a more undifferentiated processing of visual information. We propose that ethanol causes a reduced inhibition of the left posterior cortex and a reduction of right-hemisphere information processing.
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| 8. |
- Wirsen, A., et al.
(författare)
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Quantified EEG and cortical evoked responses in patients with chronic traumatic frontal lesions
- 1992
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Ingår i: Electroencephalography and Clinical Neurophysiology / Evoked Potentials Section. - : Elsevier BV. - 0168-5597. ; 84:2, s. 127-138
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Tidskriftsartikel (refereegranskat)abstract
- Eighteen frontal trauma patients and 17 age-matched control subjects had quantified EEGs and measurements of sensory (SEP) and auditory evoked potentials (P300) using a Biologic Brain Atlas III system. The findings were compared to the conventional paper EEG, and to the frontal lesion volumes, severity of head injury, and outcome variables. The quantified EEG confirmed the pathological findings detected by visual inspection, but some regional abnormalities were more easily detected by topographic mapping. The regional distribution of pathological slowing corresponded well with the morphological lesions in most patients. The modal frequency of EEG correlated both with lesion volume and injury severity and with the outcome variables. There were no pathological findings in the SEPs, and all but one patient had clearly distinguishable P300 responses. There was a significant reduction in P300 amplitude in the frontal patients at the anterior, but not at the posterior electrodes. The topographical distribution of the P300 changes corresponded well with the morphological lesions. Our findings indicate that the P300 potential is, in part, dependent upon the prefrontal cortical areas. The present study thus supports P300 investigations which have shown amplitude reduction in other disorders (e.g., schizophrenia) with a presumed prefrontal dysfunction.
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