A Stroop effect emerges in the processing of complex Chinese characters that contain a color-related radical

The presence of cognitive impairments in the acute phase of traumatic upper limb injuries: A cross-sectional observational study

OBJECTIVES

The purpose of this study was to investigate the association between cognitive impairments and traumatic upper limb injuries of the acute phase.

MATERIAL AND METHODS

A cross-sectional observational study was conducted with three groups: a nerve-injury group, a without nerve injury group, and a control group (uninjured participants). Demographic characteristics (e.g. age, sex, body mass index, and education) and traumatic characteristics (duration since injury, injury side, pain, light touch sensation, hand motor function) were recorded. Short-term memory and executive functions were assessed using Rey Auditory and Verbal Learning Test (RAVLT) and Stroop Color and Word Test (SCWT, including SIECT and SIECN), respectively.

RESULTS

The study comprised 43 participants in the nerve-injury group, 30 participants in the group without nerve injury, and 104 participants in the control group. Generalized linear model was applied to explore the difference of cognitive functions among three groups with impactors. Significantly poorer performance on the RAVLT was observed in the nerve-injury group compared to the other two groups, and lower score of SIECT in nerve-injury group was lower compared to the control group. However, there was no significant difference of SIECN among three groups. In addition, traumatic characteristics did not significantly impact RAVLT and SIECT (p > 0.05) in all injured participants.

CONCLUSION

Traumatic nerve injury to the upper limb appears to be associated with both short-term memory and executive function impairment, whereas musculoskeletal injuries without nerve damage showed no cognitive impairment. Therefore, it is important to monitor cognitive function following upper limb nerve injuries.

The impact of depressive symptoms on cognitive impairments in chronic ketamine users

BACKGROUND

Chronic ketamine use has been associated with cognitive impairments, while depressive symptoms are commonly observed in individuals using ketamine. However, the influence of depressive symptoms on cognitive impairments in chronic ketamine users remains unclear. This study aimed to examine the impact of depressive symptoms on cognitive function in this population.

METHODS

A cross-sectional study was conducted with a sample of chronic ketamine users. Participants underwent comprehensive cognitive assessments, including measures of attention, executive function, working memory, verbal and visual memory. Depressive symptoms were assessed using Beck Depression Inventory (BDI) scores. Multivariate analyses were utilized to compare the cognitive performance of individuals who use ketamine, both with and without depressive symptoms, as well as a control group, while controlling for relevant covariates.

RESULTS

The results revealed a significant negative impact of depressive symptoms on cognitive impairments, particularly in the domains of memory and executive function, among chronic ketamine users. The analysis of partial correlations revealed that among individuals who use ketamine and have depressive symptoms, those with higher levels of depressive symptoms demonstrated poorer cognitive performance compared to individuals with lower levels of depressive symptoms, controlling for potential confounding factors.

CONCLUSIONS

The findings suggest that depressive symptoms contribute to cognitive impairments, specifically in memory and executive function, in chronic ketamine users. Therefore, it is crucial to evaluate depressive symptoms when considering cognitive enhancement treatment for this population.

Effect of traumatic upper-limb injury on cognitive functions: A cross-sectional observational study

OBJECTIVES

There is growing evidence of cognitive impairment after traumatic peripheral lesions. The purpose of this study was to explore the association between cognitive function and traumatic upper-limb injury. We assessed difference in cognitive function between participants with and without upper-limb injury, and explored the association between cognitive function and certain variables in injured individuals: gender, age, body mass index (BMI), educational level, and occupation. We sought to identify the factors associated with cognitive function in injured subjects: time since injury, injury side, nerve injury, hand function, pain, and finger sensation.

MATERIAL AND METHODS

A cross-sectional observational study was conducted, with 2 groups: observational group (with traumatic upper-limb injury) and control group (uninjured). The 2 groups were matched for age, gender, BMI, educational level and occupation. Short-term memory and executive functions were assessed using the Rey Auditory and Verbal Learning Test (RAVLT) and Stroop Color and Word Test (SCWT), respectively.

RESULTS

104 participants with traumatic upper-limb injury and 104 uninjured control subjects were included. There was a significant inter-group difference only in RAVLT (p < 0.01; Cohen d, of 0.38). Regression analysis demonstrated an association of pain on VAS (beta = -0.16, p < 0.01) and touch-test (beta = 1.09, p < 0.05) with total RAVLT score (short-term memory) in injured subjects (R2 = 0.19, F (2, 82) = 9.54, p < 0.001).

CONCLUSION

Traumatic upper-limb injury can impact short-term memory, which should be kept in mind during rehabilitation.

The nature of perceptual units in Chinese character recognition

Chinese character recognition is based on a limited set of recurrent stroke patterns. Most Chinese characters are a combination of two or more of these components. To test whether readers are sensitive to combinations of components (or multi-component units [MCUs]) within a character, we conducted two probe detection tasks where participants had to detect the presence of a component in a target character. Critically, some targets contained an MCU that can stand as a character on its own, with its own meaning and sound, while other targets contained an MCU that only exists embedded within other characters (no associated meaning and sound). Participants had more difficulty detecting component probes that were a part of an existing MCU, compared to component probes that belonged to a non-existing MCU. These findings suggest that existing MCUs are a perceptual unit in Chinese character recognition.

An Investigation of Spatial Stimulus-Response Compatibility Effects Based on German Particles

In the current study, we tested if stimulus-response (SR) compatibility effects of spatially ambiguous words depend on a semantic priming context. Although many words, including spatial words, can take on several meanings, this is an open question. From Experiments 1 to 3, we manipulated the likelihood that the vertical meaning of the German particles auf and ab was processed by (1) instructing the processing of vertical meaning in Experiment 1, but not in Experiments 2 and 3, and (2) by using verbs that either primed (Experiments 1 and 2) or did not prime (Experiments 1-3) the targets' vertical meanings. Spatial SR compatibility effects resulted, regardless of whether or not the processing of the vertical meaning was instructed and the vertical meaning was primed. Results suggest that the selection between vertically discriminated responses could be sufficient to elicit the participants' extraction of the vertical meaning of the ambiguous particles.

Lexical processing of Chinese sub-character components: Semantic activation of phonetic radicals as revealed by the Stroop effect

Most Chinese characters are compounds consisting of a semantic radical indicating semantic category and a phonetic radical cuing the pronunciation of the character. Controversy surrounds whether radicals also go through the same lexical processing as characters and, critically, whether phonetic radicals involve semantic activation since they can also be characters when standing alone. Here we examined these issues using the Stroop task whereby participants responded to the ink color of the character. The key finding was that Stroop effects were found when the character itself had a meaning unrelated to color, but contained a color name phonetic radical (e.g., “guess”, with the phonetic radical “cyan”, on the right) or had a meaning associated with color (e.g., “pity”, with the phonetic radical “blood” on the right which has a meaning related to “red”). Such Stroop effects from the phonetic radical within a character unrelated to color support that Chinese character recognition involves decomposition of characters into their constituent radicals; with each of their meanings including phonetic radicals activated independently, even though it would inevitably interfere with that of the whole character. Compared with the morphological decomposition in English whereby the semantics of the morphemes are not necessarily activated, the unavoidable semantic activation of phonetic radicals represents a unique feature in Chinese character processing.

Premotor Cortex Activation Elicited during Word Comprehension Relies on Access of Specific Action Concepts

The relationship between the lexical-semantic and sensory-motor systems is an important topic in cognitive neuroscience. An important finding indicating that these two systems interact is that reading action verbs activates the motor system of the human brain. Two constraints have been proposed to modulate this activation: the effector information associated with the action concepts and statistical regularities between sublexical features and grammatical classes. Using fMRI, we examined whether these two types of information can activate the motor system in the absence of specific motor-semantic content by manipulating the existence of a sublexical cue, called the hand radical, which strongly indicates the semantic feature "hand-related" and grammatical class "verb." Although hand radical characters referring to specific manual actions evoked stronger activation in the premotor cortex than the control characters, hand radical pseudocharacters did not evoke specific activation within the motor system. These results indicated that activation of the premotor cortex during word reading relies on the access of specific action concepts.

Lack of visual field asymmetries for spatial cueing in reading parafoveal Chinese characters

In two experiments, we investigated whether visual field (VF) asymmetries of spatial cueing are involved in reading parafoveal Chinese characters. These characters are different from linearly arranged alphabetic words in that they are logograms that are confined to a constant, square-shaped area and are composed of only a few radicals. We observed a cueing effect, but it did not vary with the VF in which the Chinese character was presented, regardless of whether the cue validity (the ratio of validly to invalidly cued targets) was 1:1 or 7:3. These results suggest that VF asymmetries of spatial cueing do not affect the reading of parafoveal Chinese characters, contrary to the reading of alphabetic words. The mechanisms of spatial attention in reading parafoveal English-like words and Chinese characters are discussed.