Introduction to Autism: Neurodevelopment and Its Characteristics - Essay Sample

Introduction

Autism is a neurodevelopment condition comprising a broad array of socio-emotional deficiencies, abnormal sensory response, and the presence of repetitive or restricted interests. Many subclinical characteristics of autism are common in the general public with medical status experiencing a diagnosis of autism indicating excessive values on a continuous distribution (Stavropoulous, 2016). In a normally developing population, autistic traits are exhibited in neural performance and they are measured through Autistic-Spectrum Quotient (AQ) (Baron-Cohen, 2001). The attentional blink (AB) is the phenomenon that individuals cannot identify or recognize the second of two targets when it occurs in close succession to the first (Raymond, Shapiro, & Arnell, 1992). Many studies support the notion that differences in AQ and AB magnitudes on experiments preceded by a fearful face within people with autistic traits can be linked to brain function.

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Problems with emotional processing are normally exhibited by Autistic Spectrum Disorder (ASD) including orienting, visualising, and understanding emotional expressions that are significantly associated with bonding with others and extraction of mental states (Stavropoulous, 2016). Behaviours of emotional expressions include emotional vocalisations, body language, and facial expressions, which are instinctual and involuntary actions as a result of neural processes. People with autistic traits show atypical neural action in reaction to emotional faces despite behavioural indicators of emotion matching being intact. According to McPartland et al (2011), data from temporal neuroimaging methods show that face processing is deferred in individuals exhibiting autistic traits. Provided that previous results indicate that autistic individual’s process faces at a slower rate than their peers; this is significant in comprehending the neural systems that underlie slow face processing in ASD. For instance, attentional blink has been utilised to explore variations in the neural correlates of intentional and automatic processing.

An experiment by Rinehart et al. (2009), established that people with ASD and autistic traits, in general, were deficient than the comparison group at identifying black As while being as good in reacting to white letters, which was accounted for in the framework of probable dual-task processing problems or pictorial search authority. Autistic children and adults have issues with facial expression recognition, yet this finding cannot be generalized. A study by Gaigg & Bowler (2009), found an intact AB impact with neutral words but did not exhibit a low AB outcome for recognising emotional words implying that visual attention in autistic people is selectively interrupted for emotional data. Conversely, Monk et al (2010), demonstrated that adults with autism have intact spatial attention preference to faces with emotional expressions. Vermeulen et al. (2009) argue that facial expression processing is connected to AB size, which can be experimented by assessing the impacts of fearful faces on the attentional blink across people with ASD or autistic traits, who are thought to have problems in processing emotional information than others groups.

The present study evaluated the emotional variation of the AB effect in people with autistic traits. It is imperative to examine this effect in individuals with autistic traits for some reason. First, there are no studies that measure the magnitude or size of the AB by deducting the accurateness on tests when the interval between T1 and T2 was long (670ms) and comparing them with when T1 and T2 are short (134ms). Further, measuring the study sample autistic traits by using the AQ scale. And comparing the relationship and differences between the AB and AQ concerning participant age, AQ score, AQ group, and performance on the emotion matching task. Batty & Taylor (2006) posits that visual processing of emotional faces happens to be more effective and efficient with age and intentional attention is lower for angry than happy adult faces. Therefore, it is probable that trials heralded by fearful faces can demonstrate the relationship between differences in AQ and AB size.

Methods

Participants

191 participants participated in the study, 52 male, 137 females, and 2 not stated between the ages of 18-47 years completed the experiment as part of a tutorial in their PSYC 2203 unit. All participants gave written informed consent before testing. The procedure was conducted in accordance with the Declaration of Helsinki and approved by the University of Western Australia's Human Research Ethics Committee.

Stimulus and Procedure

All testing was conducted on PC computers, running Windows 11, and connected to 22” monitors. At a viewing distance of approximately 50 cm, all stimuli subtended approximately 1o of visual angle.

Each trial began with a centrally-presented fixation cross with participants initiating the stimulus presentation at their leisure by pressing the space bar. This initiated the presentation of a prime face that had one of two emotional expressions fearful and happy for 1000 ms. The fixation was then presented for a further 500 ms, and then the rapid serial visual presentation (RSVP) stream began. Each item in the RSVP was presented for 68 ms and followed immediately by the next item. The RSVP began with a sequence of 9 to 12 distractor items consisting of either keyboard symbols or pseudoletters (random shapes made from letter parts). The first letter target (T1) was then presented, followed by a single digit that acted as a mask, and then one of six additional distractor items (yielding two inter-target lags: short vs long), followed by the second letter target (T2) and a single-digit mask.

After the last RSVP item disappeared, participants were prompted to report the identity of the first and second targets by pressing keys on the keyboard. They were then presented with a probe face and asked to report whether it had the same emotional expression as the face presented at the beginning of the trial or not. They indicated this decision by pressing either the left arrow key (to indicate an identical expression) or the right arrow key (to indicate a different expression). Following this last response, the fixation cross reappeared, and participants could begin the next trial.

Participants completed 192 trials, divided into 3 blocks of 64 trials. Each block was separated by a short break period whose length was determined by the participant. Equal numbers of trials were presented across each combination of inter-target lag and prime emotional expression yielding six trials per combination of these two factors. The total testing time was approximately 20 minutes.

Results

The study found that the mean age of the participants was 20.9, with a median of 19, and a mode of 19 years as seen in table 1. Therefore, the majority of the participants were young people.

Table 2 as seen below represent the Autistic Spectrum Quotient scores of the participants. The lowest score was 68, while the highest score was 180. The lowest scores indicate that the participant has low autistic traits while a higher score means that they have high-level autistic traits. Those around the mean of 110 ere categorised as middle AQ implying that they exhibit neither or low autistic traits. Figure 1 demonstrates that the AQ distribution among the participants was normal.

Figure 1: Participants AQ Distribution

All the participants’ scores on the attentional blink were recorded with a mean of 37.4 across all the three AQ groups (Table 3). The lowest score was -5.10, while the highest score was 87.3. Besides, the AB magnitudes were normally distributed as seen in figure 2.

Figure 2: AB Magnitude distribution

The study found that there were apparent differences in the three AQ groups which are low, middle, and high autistic traits participants as observed in figure 3. The low AQ group scored relatively higher than the rest of the group with a mean of 41.8 in emotional processing, which is higher than the rest. Therefore, participants with low autistic traits performed better in recognising the second target appearing in a succession of the first target when preceded with a fearful face. Those with middle AQ scores also performed relatively better than those with low AQ scores with a mean score of 38.3 against 32.3 in emotional processing (Table 4; Appendix 3). Therefore, the attentional blink magnitude was low in people with a high level of autistic traits.

The ANOVA p-value was found to be less than the significance level as indicated in figure 4. This shows that the AQ groups' means differences are statistically significant concerning AB magnitude. However, the p-value of emotional recognition accuracy was 0.935, which means that the groups’ differences are not statistically significant (Appendix 1, Appendix 2, Appendix 4; Appendix 5).

Figure 3: AB Magnitude Differences among the three groups

Figure 4: One-Way ANOVA (Welch's)

Discussion

The study accessed the possible effect of changing levels of autistic-like traits on the stimulus of the emotional face. The size of the AB impact for a second target preceded by a fearful face was different in the three AQ groups. As such, this study has shown that there are relationship differences in low, middle, and higher AQ groups and AB magnitude on trials preceded by fearful face. Besides, AB effect was increased for people exhibiting low autistic traits, which demonstrate that visual attention to emotional information is maintained in non-autistic people or people with low autistic traits, while those diagnosed with ASD tend to lack sufficient visual attention to emotional information. Thus, people with higher autistic traits tend to have reduced emotional processing, which is explained by the way they tend to process the stimuli. Further, the analysis found that emotion recognition accuracy among the three AQ groups was not statistically significant. This lack of groups’ differences in the AB size for fearful emotion...