The representation of abstract words: why emotion matters

Although much is known about the representation and processing of concrete concepts, knowledge of what abstract semantics might be is severely limited. In this article we first address the adequacy of the 2 dominant accounts (dual coding theory and the context availability model) put forward in order to explain representation and processing differences between concrete and abstract words. We find that neither proposal can account for experimental findings and that this is, at least partly, because abstract words are considered to be unrelated to experiential information in both of these accounts. We then address a particular type of experiential information, emotional content, and demonstrate that it plays a crucial role in the processing and representation of abstract concepts: Statistically, abstract words are more emotionally valenced than are concrete words, and this accounts for a residual latency advantage for abstract words, when variables such as imageability (a construct derived from dual coding theory) and rated context availability are held constant. We conclude with a discussion of our novel hypothesis for embodied abstract semantics.     

Remembering words not presented in sentences: How study context changes patterns of false memories

People falsely endorse semantic associates and morpheme rearrangements of studied words at high rates in recognition testing. The coexistence of these results is paradoxical: Models of reading that presume automatic extraction of meaning cannot account for elevated false memory for foils that are related to studied stimuli only by their visual form; models without such a process cannot account for false memory for semantic foils. Here we show how sentence and list study contexts encourage different encoding modes and consequently lead to different patterns of memory errors. Participants studied compound words, such as tailspin and floodgate, as single words or embedded in sentences. We show that sentence contexts led subjects to be better able to discriminate conjunction lures (e.g., tailgate) from old words than did list contexts. Conversely, list contexts led to superior discrimination of semantic lures (e.g., nosedive) from old words than did sentence contexts.     

Emotional stimuli modulate readiness for action: A transcranial magnetic stimulation study

Emotional stimuli may prime the motor system and facilitate action readiness. Direct evidence for this effect has been shown by recent studies using transcranial magnetic stimulation (TMS). When administered over the primary motor cortex involved in responding, TMS pulses elicit motor-evoked potentials (MEPs) in the represented muscles. The amplitudes of these MEPs reflect the state of corticospinal excitability. Here, we investigated the dynamic effects of induced emotions on action readiness, as reflected by corticospinal excitability. Subjects performed a choice task while viewing task-irrelevant emotional and neutral pictures. The pattern of MEP amplitudes showed a typical increase as the TMS pulse was presented closer in time to the imminent response. This dynamic pattern was amplified by both pleasant and unpleasant emotional stimuli, but more so when unpleasant pictures were viewed. These patterns present novel evidence in support of the notion that emotional stimuli modulate action readiness.     

When words collide: facilitation and interference in the report of repeated words from rapidly presented lists

Inhibited encoding is the basis of some accounts of repetition blindness--impaired report of the second occurrence of a repeated word in a rapidly presented word sequence. The author presents evidence for the claim that repetition effects arise from constructive processes of perception and memory that occur to some extent after the word sequence has been presented. Unpredictable postlist cues prompted subjects to report either the entire list or just the final word in the list. Repetition impaired the report of the second occurrence of a repeated word under full report but facilitated the report of such items when only the final word had to be reported. The author modulated this dissociation by presenting repeated words in sentences rather than unrelated word lists. The sensitivity of the effects of repetition to postlist cues supports a construction rather than an encoding inhibition account of repetition blindness.     

Priming complex words: evidence for supralexical representation of morphology

Effects of morphologically related primes were examined in two masked prime experiments. Responses to both free root and derived suffixed word targets were facilitated when primes were derived suffixed words containing the target’s root, and this facilitation effect showed a time course similar to that for the facilitation effect of repetition primes (though systematically smaller in magnitude). In a control experiment only the longest prime duration of Experiment 1 was used; responses to derived suffixed word targets were facilitated by both free root primes and derived suffixed word primes sharing the target’s root (relative to unrelated and form-related control primes). The free root and derived suffixed word prime conditions did not differ significantly. In Experiment 2, only true derived word primes produced facilitation, whereas morphologically simple primes containing a pseudoroot did not influence performance relative to the unrelated prime condition. We argue that this supports a supralexical account of morphological representation.     

Clauses and the semantic representation of words

When a sentence with more than one clause is processed, words of the first clause become less available for recall or recognition once the clause boundary has been passed. One common interpretation of this observation is that the representation of a given word shifts from a predominantly surface form (e.g., phonological or lexical) to a semantic form, after the clause boundary. Two experiments that test that interpretation are reported. In the first experiment, two-clause spoken sentences were followed by spoken word or picture probes. Pictures were intended to provide a fast semantic match to probed words, but a slow surface match. Although response times exhibited a robust main effect of the clause position of the probe, no interaction with probe type was found. Similar results were obtained in a second experiment that compared pictures with written word probes. The faster response to picture than to word probes in the second experiment indicates that subjects did not covertly name the picture, but made a semantic match (as intended). These observations suggest the following reinterpretation of earlier sentence memory experiments: Words in the most recent clause of a sentence are more available than words in an earlier clause because their semantic representations are more active, not because their surface representations are more active.     

Perceptual specificity of priming for compound words not presented

Two experiments extended prior work on the perceptual specificity of priming to compound words not presented during a study phase. In both experiments, perceptual manipulations were employed, and priming was obtained on a word fragment completion test (e.g.,c_ec_po_nt) where the lexical elements of the compounds (check andpoint) were presented in different study words. In Experiment 1, priming was highest when identical fragments for the lexical components were presented during the study phase (c_ec_list, needlepo_nt) and test phase (c_ec_po_nt). In Experiment 2, visual study presentations, but not auditory study presentations, led to significant priming. The findings are consistent with predictions from transfer-appropriate processing and demonstrate perceptual, not lexical (postperceptual), priming.     

Processing of words presented simultaneously to eye and ear

The simultaneous processing of auditorily and visually presented messages was examined in three experiments. Subjects searched lists of words for a target word while processing auditorily presented information. Across conditions, subjects searched for (a) target words in a list of words presented auditorily, (b) the same target words in lists presented visually, (c) a member of a taxonomic category in a visually presented list, and (d) a rhyme in a list of words presented visually. The level of processing of a simultaneous auditory message varied across experiments. In experiment 1, subjects shadowed lists of digits. In Experiment 2, subjects reported the antonym of each word in a list. In Experiment 3, subjects named the taxonomic category of each word in a list. In all three experiments, subject had high detection rates for target words presented visually and for category targets but low detection rates for target words presented auditorily and for rhyme targets. These results suggest that processing the semantic properties, but not the acoustic properties, of words presented to the visual modality is independent of simultaneous processing in the auditory modality. Implication for models of selective attention are discussed.     

Learning and retrieval rate of words presented auditorily and visually

Mode of presentation (visual or auditory) of a multitrial free recall test is stressed as an important factor in improving the diagnosis of certain neurological patients. For further use in neuropsychological research, an experiment was carried out using normal subjects, in which the effects of presentation mode and order of modality were investigated. There were no differential effects of these variables on several parameters, such as the number of words recalled and the learning curve. The time needed for the responses in immediate recall was the same in both auditory and visual conditions. In delayed recall, however, the interresponse times were significantly shorter when words had been presented auditorily than when presented visually. The results are discussed in light of further application in the field of neuropsychology.     

The format of representation of recognized words in infants' early receptive lexicon

Eleven-month-olds can recognize a few auditorily presented familiar words in experimental situations where no hints are given by the intonation, the situation, or the presence of possible visual referents. That is, infants of this age (and possibly somewhat younger) can recognize words based on sound patterns alone. The issue addressed in this article is what is the type of mental representations infants use to code words they recognize. The results of a series of experiments with French-learning infants indicate that word representations in 11-month-olds are segmentally underspecified and suggest that they are all the more underspecified when infants engage in recognizing words rather than merely attending to meaningless speech sounds. But underspecification has limits, which were explored here with respect to word-initial consonants. The last two experiments show the way to investigating further these limits for word-initial consonants as well as for segments in other word positions. In French, infants' word representations are flexible enough to allow for structural changes in the voicing or even in the manner of articulation of word-initial consonants. Word-initial consonants must be present, however, for words to be recognized. In conclusion, a parallel is proposed between the emerging capacities to ignore variations that are irrelevant for word recognition in a “lexical mode” and to ignore variations that are phonemically irrelevant in a “neutral mode” of listening to native speech.     

A magnetic resonance imaging study of regional cortical volumes following stereotactic anterior cingulotomy

The purpose of this study was to test the hypothesis that orbitofrontal cortical volume would be reduced following anterior cingulotomy for obsessive-compulsive disorder (OCD). Whole brain cortical parcellation was performed on magnetic resonance imaging (MRI) data from nine patients, before and 9 (+/-6) months following anterior cingulotomy. No significant volumetric reductions were found in the orbitofrontal cortex. Exploratory findings of reduced volume in ventral temporo-fusiform and posterior cingulate regions were consistent with chance differences, in the face of multiple comparisons. Therefore, though the circumscribed lesions of anterior cingulotomy have recently been associated with corresponding volumetric reductions in the caudate nucleus, no comparable volumetric reductions are evident in cortical territories. Taken together, these results are most consistent with a model of cingulo-striatal perturbation as a putative mechanism for the efficacy of this procedure. While limitations in sensitivity may have also contributed to these negative findings, the methods employed have previously proven sufficient to detect cortical volumetric abnormalities in OCD. The current results may reflect a relatively diffuse pattern of cortico-cortical connections involving the neurons at the site of cingulotomy lesions. Future functional neuroimaging studies are warranted to assess possible cortical or subcortical metabolic changes associated with anterior cingulotomy, as well as predictors of treatment response.     

Emotion and motor preparation: A transcranial magnetic stimulation study of corticospinal motor tract excitability

In the present study, we examined whether preparing motor responses under different emotional conditions alters motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation delivered to the motor cortex. Analyses revealed three findings: (1) Reaction times were expedited during exposure to unpleasant images, as compared with pleasant and neutral images; (2) force amplitude was greater during exposure to unpleasant images, as compared with pleasant and neutral images; and (3) MEPs were larger while participants viewed unpleasant images, as compared with neutral images. Hence, coupling the preparation of motor responses with the viewing of emotional images led to arousal-driven changes in corticospinal motor tract excitability, whereas movement speed and force production varied as a function of emotional valence. These findings demonstrate that the effects of emotion on the motor system manifest at varying sensitivity levels across behavioral and neurophysiological measures. Moreover, they validate the action readiness component of emotional experience by demonstrating that emotional states influence the execution of future movements but, alone, do not lead to overt movement.     

Buzzwords: early cortical responses to emotional words during reading

Electroencephalographic event-related brain potentials were recorded as subjects read, without further instruction, consecutively presented sequences of words. We varied the speed at which the sequences were presented (3 Hz and 1 Hz) and the words' emotional significance. Early event-related cortical responses during reading differentiated pleasant and unpleasant words from neutral words. Emotional words were associated with enhanced brain responses arising in predominantly left occipito-temporal areas 200 to 300 ms after presentation. Emotional words were also spontaneously better remembered than neutral words. The early cortical amplification was stable across 10 repetitions, providing evidence for robust enhancement of early visual processing of stimuli with learned emotional significance and underscoring the salience of emotional connotations during reading. During early processing stages, emotion-related enhancement of cortical activity along the dominant processing pathway is due to arousal, rather than valence of the stimuli. This enhancement may be driven by cortico-amygdaloid connections.     

Bounding of letter sequences and the integration of visually presented words

Ss wrote down letters that were presented briefly in various temporal and geometric arrangements. Results reveal marked impairment in processing more than one temporally extended word in parallel. The impairment cannot be attributed to spatial separation of letters by itself, to sequence, or to inability to discriminate the letters. The concept of ‘bounding’ is introduced to account for the perception of familiar words in a continuing flow of information; the results suggest that only one object can be bounded at a time. They also suggest that the information that guides the eyes' movements in reading is qualitatively different from the information extracted from the printed text.     

Sleep-associated changes in the mental representation of spoken words

The integration of a newly learned spoken word form with existing knowledge in the mental lexicon is characterized by the word form's ability to compete with similar-sounding entries during auditory word recognition. Here we show that although the mere acquisition of a spoken form is swift, its engagement in lexical competition requires an incubation-like period that is crucially associated with sleep. Words learned at 8 p.m. do not induce (inhibitory) competition effects immediately, but do so after a 12-hr interval including a night's sleep, and continue to induce such effects after 24 hr. In contrast, words learned at 8 a.m. do not show such effects immediately or after 12 hr of wakefulness, but show the effects only after 24 hr, after sleep has occurred. This time-course dissociation is best accommodated by connectionist and neural models of learning in which sleep provides an opportunity for hippocampal information to be fed into long-term neocortical memory.