Open Access
Refine
Year of publication
Document Type
- Article (29)
- Postprint (8)
- Monograph/Edited Volume (1)
Language
- English (38)
Is part of the Bibliography
- yes (38)
Keywords
- eye movements (4)
- individual differences (4)
- reading (4)
- DLT (3)
- Spanish (3)
- activation (3)
- antilocality (3)
- child language (3)
- discourse (3)
- expectation (3)
Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single- (ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 ± 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2–21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9–2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3–4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9–3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.
Postural control is important to cope with demands of everyday life. It has been shown that both attentional demand (i.e., cognitive processing) and fatigue affect postural control in young adults. However, their combined effect is still unresolved. Therefore, we investigated the effects of fatigue on single- (ST) and dual-task (DT) postural control. Twenty young subjects (age: 23.7 ± 2.7) performed an all-out incremental treadmill protocol. After each completed stage, one-legged-stance performance on a force platform under ST (i.e., one-legged-stance only) and DT conditions (i.e., one-legged-stance while subtracting serial 3s) was registered. On a second test day, subjects conducted the same balance tasks for the control condition (i.e., non-fatigued). Results showed that heart rate, lactate, and ventilation increased following fatigue (all p < 0.001; d = 4.2–21). Postural sway and sway velocity increased during DT compared to ST (all p < 0.001; d = 1.9–2.0) and fatigued compared to non-fatigued condition (all p < 0.001; d = 3.3–4.2). In addition, postural control deteriorated with each completed stage during the treadmill protocol (all p < 0.01; d = 1.9–3.3). The addition of an attention-demanding interference task did not further impede one-legged-stance performance. Although both additional attentional demand and physical fatigue affected postural control in healthy young adults, there was no evidence for an overadditive effect (i.e., fatigue-related performance decrements in postural control were similar under ST and DT conditions). Thus, attentional resources were sufficient to cope with the DT situations in the fatigue condition of this experiment.
Are individual differences in reading speed related to extrafoveal visual acuity and crowding?
(2015)
Readers differ considerably in their speed of self-paced reading. One factor known to influence fixation durations in reading is the preprocessing of words in parafoveal vision. Here we investigated whether individual differences in reading speed or the amount of information extracted from upcoming words (the preview benefit) can be explained by basic differences in extrafoveal vision-i.e., the ability to recognize peripheral letters with or without the presence of flanking letters. Forty participants were given an adaptive test to determine their eccentricity thresholds for the identification of letters presented either in isolation (extrafoveal acuity) or flanked by other letters (crowded letter recognition). In a separate eye-tracking experiment, the same participants read lists of words from left to right, while the preview of the upcoming words was manipulated with the gaze-contingent moving window technique. Relationships between dependent measures were analyzed on the observational level and with linear mixed models. We obtained highly reliable estimates both for extrafoveal letter identification (acuity and crowding) and measures of reading speed (overall reading speed, size of preview benefit). Reading speed was higher in participants with larger uncrowded windows. However, the strength of this relationship was moderate and it was only observed if other sources of variance in reading speed (e.g., the occurrence of regressive saccades) were eliminated. Moreover, the size of the preview benefit-an important factor in normal reading-was larger in participants with better extrafoveal acuity. Together, these results indicate a significant albeit moderate contribution of extrafoveal vision to individual differences in reading speed.
Are Individual Differences in Reading Speed Related to Extrafoveal Visual Acuity and Crowding?
(2015)
Readers differ considerably in their speed of self-paced reading. One factor known to influence fixation durations in reading is the preprocessing of words in parafoveal vision. Here we investigated whether individual differences in reading speed or the amount of information extracted from upcoming words (the preview benefit) can be explained by basic differences in extrafoveal vision-i.e., the ability to recognize peripheral letters with or without the presence of flanking letters. Forty participants were given an adaptive test to determine their eccentricity thresholds for the identification of letters presented either in isolation (extrafoveal acuity) or flanked by other letters (crowded letter recognition). In a separate eye-tracking experiment, the same participants read lists of words from left to right, while the preview of the upcoming words was manipulated with the gaze-contingent moving window technique. Relationships between dependent measures were analyzed on the observational level and with linear mixed models. We obtained highly reliable estimates both for extrafoveal letter identification (acuity and crowding) and measures of reading speed (overall reading speed, size of preview benefit). Reading speed was higher in participants with larger uncrowded windows. However, the strength of this relationship was moderate and it was only observed if other sources of variance in reading speed (e.g., the occurrence of regressive saccades) were eliminated. Moreover, the size of the preview benefit-an important factor in normal reading-was larger in participants with better extrafoveal acuity. Together, these results indicate a significant albeit moderate contribution of extrafoveal vision to individual differences in reading speed.
Parameters of a formal working-memory model were estimated for verbal and spatial memory updating of children. The model proposes interference though feature overwriting and through confusion of whole elements as the primary cause of working-memory capacity limits. We tested 2 age groups each containing 1 group of normal intelligence and 1 deficit group. For young children the deficit was developmental dyslexia; for older children it was a general learning difficulty. The interference model predicts less interference through overwriting but more through confusion of whole elements for the dyslexic children than for their age-matched controls. Older children exhibited less interference through confusion of whole elements and a higher processing rate than young children, but general learning difficulty was associated with slower processing than in the age-matched control group. Furthermore, the difference between verbal and spatial updating mapped onto several meaningful dissociations of model parameters.
Children's poor performance on object relative clauses has been explained in terms of intervention locality. This approach predicts that object relatives with a full DP head and an embedded pronominal subject are easier than object relatives in which both the head noun and the embedded subject are full DPs. This prediction is shared by other accounts formulated to explain processing mechanisms. We conducted a visual-world study designed to test the off-line comprehension and on-line processing of object relatives in German-speaking 5-year-olds. Children were tested on three types of object relatives, all having a full DP head noun and differing with respect to the type of nominal phrase that appeared in the embedded subject position: another full DP, a 1st- or a 3rd-person pronoun. Grammatical skills and memory capacity were also assessed in order to see whether and how they affect children's performance. Most accurately processed were object relatives with 1st-person pronoun, independently of children's language and memory skills. Performance on object relatives with two full DPs was overall more accurate than on object relatives with 3rd-person pronoun. In the former condition, children with stronger grammatical skills accurately processed the structure and their memory abilities determined how fast they were; in the latter condition, children only processed accurately the structure if they were strong both in their grammatical skills and in their memory capacity. The results are discussed in the light of accounts that predict different pronoun effects like the ones we find, which depend on the referential properties of the pronouns. We then discuss which role language and memory abilities might have in processing object relatives with various embedded nominal phrases.
Children’s poor performance on object relative clauses has been explained in terms of intervention locality. This approach predicts that object relatives with a full DP head and an embedded pronominal subject are easier than object relatives in which both the head noun and the embedded subject are full DPs. This prediction is shared by other accounts formulated to explain processing mechanisms. We conducted a visual-world study designed to test the off-line comprehension and on-line processing of object relatives in German-speaking 5-year-olds. Children were tested on three types of object relatives, all having a full DP head noun and differing with respect to the type of nominal phrase that appeared in the embedded subject position: another full DP, a 1st- or a 3rd-person pronoun. Grammatical skills and memory capacity were also assessed in order to see whether and how they affect children’s performance. Most accurately processed were object relatives with 1st-person pronoun, independently of children’s language and memory skills. Performance on object relatives with two full DPs was overall more accurate than on object relatives with 3rd-person pronoun. In the former condition, children with stronger grammatical skills accurately processed the structure and their memory abilities determined how fast they were; in the latter condition, children only processed accurately the structure if they were strong both in their grammatical skills and in their memory capacity. The results are discussed in the light of accounts that predict different pronoun effects like the ones we find, which depend on the referential properties of the pronouns. We then discuss which role language and memory abilities might have in processing object relatives with various embedded nominal phrases.
Children’s poor performance on object relative clauses has been explained in terms of intervention locality. This approach predicts that object relatives with a full DP head and an embedded pronominal subject are easier than object relatives in which both the head noun and the embedded subject are full DPs. This prediction is shared by other accounts formulated to explain processing mechanisms. We conducted a visual-world study designed to test the off-line comprehension and on-line processing of object relatives in German-speaking 5-year-olds. Children were tested on three types of object relatives, all having a full DP head noun and differing with respect to the type of nominal phrase that appeared in the embedded subject position: another full DP, a 1st- or a 3rd-person pronoun. Grammatical skills and memory capacity were also assessed in order to see whether and how they affect children’s performance. Most accurately processed were object relatives with 1st-person pronoun, independently of children’s language and memory skills. Performance on object relatives with two full DPs was overall more accurate than on object relatives with 3rd-person pronoun. In the former condition, children with stronger grammatical skills accurately processed the structure and their memory abilities determined how fast they were; in the latter condition, children only processed accurately the structure if they were strong both in their grammatical skills and in their memory capacity. The results are discussed in the light of accounts that predict different pronoun effects like the ones we find, which depend on the referential properties of the pronouns. We then discuss which role language and memory abilities might have in processing object relatives with various embedded nominal phrases.
Linked linear mixed models
(2016)
The complexity of eye-movement control during reading allows measurement of many dependent variables, the most prominent ones being fixation durations and their locations in words. In current practice, either variable may serve as dependent variable or covariate for the other in linear mixed models (LMMs) featuring also psycholinguistic covariates of word recognition and sentence comprehension. Rather than analyzing fixation location and duration with separate LMMs, we propose linking the two according to their sequential dependency. Specifically, we include predicted fixation location (estimated in the first LMM from psycholinguistic covariates) and its associated residual fixation location as covariates in the second, fixation-duration LMM. This linked LMM affords a distinction between direct and indirect effects (mediated through fixation location) of psycholinguistic covariates on fixation durations. Results confirm the robustness of distributed processing in the perceptual span. They also offer a resolution of the paradox of the inverted optimal viewing position (IOVP) effect (i.e., longer fixation durations in the center than at the beginning and end of words) although the opposite (i.e., an OVP effect) is predicted from default assumptions of psycholinguistic processing efficiency: The IOVP effect in fixation durations is due to the residual fixation-location covariate, presumably driven primarily by saccadic error, and the OVP effect (at least the left part of it) is uncovered with the predicted fixation-location covariate, capturing the indirect effects of psycholinguistic covariates. We expect that linked LMMs will be useful for the analysis of other dynamically related multiple outcomes, a conundrum of most psychonomic research.