The olfactory system

The olfactory system provides numerous functions to humans, influencing ingestive behavior, awareness of environmental hazards, and social communication.

The olfactory system is important for detecting food and providing good taste quality, for avoiding potentially dangerous situations in long- and short distances, like fire and microbial threats. Additionally, olfaction seems to play a key role in partner choice and helps to detect emotions in other people.

Olfactory Cortex ia Vital for the processing and perception of odor. Is a component of the limbic system. This system is involved in the processing of our emotions, survival instincts, and memory formation and connects senses, such as odors, to our memories and emotions.

To date, only one study has investigated this issue using functional magnetic resonance imaging (fMRI). The present study utilized a sophisticated method−a pulse ejection system−to present well-controlled odor stimuli to participants with ASD. With this system, we examined their odor detection, identification, and evaluation abilities and measured their brain activity evoked by odors using functional near-infrared spectroscopy (fNIRS). As the odor detection threshold (DT) of participants with ASD was highly variable, these participants were divided into two groups according to their DT: an ASD-Low DT group and an ASD-High DT group. Behavioral results showed that the ASD-High DT group had a significantly higher DT than the typically developing (control) group and the ASD-Low DT group, indicating their insensitivity to the tested odors. In addition, while there was no significant difference in the odor identification ability between groups, there was some discrepancy between the groups’ evaluations of odor pleasantness. The brain data identified, for the first time, that neural activity in the right dorsolateral prefrontal cortex (DLPFC) was significantly weaker in the ASD-High DT group than in the control group. Moreover, the strength of activity in the right DLPFC was negatively correlated with the DT. These findings suggest that participants with ASD have impairments in the higher-order function of olfactory processing, such as olfactory working memory and/or attention.

overresponsive

For individuals with an over-responsive olfactory system, smells may be a constant source of overstimulation. A functioning olfactory system assists people in identifying the “good” smells (smells that are safe, pleasant, and connected with positive emotions) from the “bad” smells (smells that are unpleasant, displeasing, or reminders of negative experiences). When the olfactory system is over-responsive not only are odors more intense, but associations made between scents and emotions they experience can become more extreme for them. Smells may be continuously overwhelming for them, and they may tend to avoid situations that have strong smells such as kitchens or bathrooms.

    • Certain scents, such as lavender, can be particularly calming and can promote better sleep

    • Comfort items such as stuffed animals, blankets or clothes with faint smells

  • Food with little to no scent:

    Activities + Items with little to no scent:

    • Pay Attention to Personal Hygiene

      • There are many products available today that have been designed specifically for to maintain good hygiene while remaining scent-free like deodorant, toothpaste, body wash and shampoo

    • Avoid areas with smoke (campfire smoke, smoking activities, etc)

    • Use Scent Reduction Products

      • You may benefit from using supplemental scent reduction products to help your space or items be scent-free. For instance, you may use a scent-eliminating spray on your clothing which can be quite effective at removing scent picked up from your body by clothing worn during the day

    • Water based activities (swimming, bathing, showering, playing with water etc)

    • Some arts and crafts

    • Avoid mixing odors – for example, burning a vanilla-scented candle while also preparing a stir fry with Asian seasonings.

    • Practice Breathing through mouth to block smell during smelly-triggering activity

    • keep rooms well ventilated, use a fan for fresh air and sit beside an open window

    • covering nose with comfort items, pillow, or clothes

    • Make the environment as fragrance-free as possible:

    • Use un-perfumed toiletries

    • seat away from the rubbish bin or other objects that may produce strong odors

underresponsive

Under-responsive means that they do not notice and process information received from the senses as well. They often seek extra sensory input or they might need support from others to register sensory input.

Those who are under-responsive to olfactory sensory input may have significant difficulty with detecting smells. This is important to note because a decreased ability to detect smells could result in exposing oneself to dangerous or poisonous substances. You may notice individuals with under-responsiveness always smelling people or objects, or misidentifying smells. When interacting with new objects, they might greet the object with their nose by immediately smelling it.

They may:

  • Enjoy strong scents

  • Not notice “dangerous” smells, for example, chemicals, gas, permanent markers, etc.

  • Crave certain smells

Examples of Olfactory Stimming by Dawnna @rawlychronic