Intangible Assets

In connection with our acquisitions of Silicon Image, Inc. in March 2015 and SiliconBlue Technologies, Inc. in December 2011, we recorded identifiable intangible assets related to developed technology, customer relationships, licensed technology, patents, and in-process research and development based on guidance for determining fair value under the provisions of ASC 820, "Fair Value Measurements." We are amortizing the intangible assets using the straight-line method over their estimated useful lives.

We monitor the carrying value of our intangible assets for potential impairment and test the recoverability of such assets annually during the fourth quarter and whenever triggering events or changes in circumstances indicate that their carrying amounts may not be recoverable. No impairment charges relating to intangible assets were recorded for the first three months of either fiscal 2019 or fiscal 2018 as no indicators of impairment were present.

On our Consolidated Balance Sheets at March 30, 2019 and December 29, 2018, Intangible assets, net are shown net of accumulated amortization of $117.2 million and $114.5 million, respectively.

We recorded amortization expense related to intangible assets on the Consolidated Statements of Operations as presented in the following table:



	Three Months Ended
(In thousands)	March 30, 2019		March 31, 2018
Research and development	$	14	$	127
Amortization of acquired intangible assets	3,389		5,636
	$	3,403	$	5,763